<p id="isPasted">People living with disabilities don't want special treatment; they want equal opportunity. The ability to act independently of, and at the same time connect with, others when moving, communicating, learning, working, and socializing.</p><p>Technology is making this increasingly viable, as assistive and adaptive technologies create a more accessible world for people living with a range of disabilities, including limb differences, motor neuron disease, as well as the blind and deaf.</p><p>Much of this development has focused on smartphones and computers, but wireless IoT technology also plays its role.</p><h2>The world around us</h2><p>Connected technologies such as environmental sensors, smart objects, and wearables are powerful tools. They can provide various inclusive and assistive information services in near real-time and connect people with disabilities with their work, home, and other environments:</p><ul><li>Indoor and outdoor wayfinding solutions employing computer vision, augmented reality, and wireless optical communications are assisting the visually impaired navigate their way from home to work and back again</li><li>Clothing embedding haptic stimulation sensors can enable the deaf to 'feel the beat' of a musical performance</li><li>Robotic limbs and bionic exoskeletons are giving the wearer control of their environment and the ability to stand and walk</li></ul><h2>Wearables for tackling MND</h2><p>Nordic Semiconductor has been working closely with customers who develop wireless solutions for those living with a disability. One such company is Control Bionics, whose wearable assistive technology offers people with amyotrophic lateral sclerosis (ALS)—also known as motor neuron disease (MND)—the ability to communicate despite paralysis or loss of speech. The small, non-invasive sensor is placed on the skin over the muscle chosen to be the switch. When the user attempts to move that muscle, the device interprets the signals sent from the brain to the muscle and uses those signals to control a paired computer, tablet, or smartphone wirelessly.</p><h2>Bluetooth LE bionic arms</h2><p>Another example is U.S. non-profit organization, Limbitless Solutions, which creates personalized bionic arms for children suffering from limb differences. The prosthetic limbs employ electromyographic (EMG) sensors to pick up signals generated by muscle movements in the wearer's upper arm. The forearm section of the bionic arm contains a battery pack that powers the motors controlling the different movements, while the hand unit includes the core electronics and motors for the fine control of the individual fingers. Bluetooth LE connectivity enables set-up, adjustment, and monitoring of the arm from a smartphone app, for example, to precisely determine the degree of muscle flexing required to generate a certain force in the fingers, and to help the child learn how to manipulate their new arm.</p><h2>Next-gen connectivity solutions</h2><p>Bluetooth LE wireless connectivity and next-generation SoCs play an essential role in ensuring the viability of these and other technologies for end-users living with disabilities. They provide a low latency wireless link to a smartphone or tablet for ease of control, and also low power consumption in an ultra-miniaturized form factor.</p><p>Avoiding having to charge our devices frequently is a significant advantage to any user, and none of us want a clunky wearable that is uncomfortable to wear. Still, the benefits are more fundamental when that device is in near-constant use or is relied upon for daily life. For example, bionic arms must be comfortable, lightweight, and easy to use, particularly for children. Smartwatches for the blind, meanwhile, must be able to last at least a full day on a single charge.</p><p>As these assistive technologies become more sophisticated and ambitious in their scope, wireless SoCs will need to keep pace. Nordic's new nRF53 Series has been designed to meet the likely requirements of developers in the future. It offers a new flexible, dual-processor hardware architecture, low power, and the ability to support miniaturized machine learning, edge processing, and LE Audio.</p><h2>The promise of LE Audio</h2><p>LE Audio, for instance, has the potential to significantly improve the experience of users of hearing aids and hearing implants by supporting a feature called Audio Sharing. Thanks to LE Audio, people with hearing loss will be able to realize the same benefits of Bluetooth audio enjoyed by users of standard Bluetooth headphones and earbuds, including wireless calling, listening, and watching. Audio Sharing will enable an advanced new type of Assistive Listening Systems with higher audio quality and greater privacy that avoids the challenges of sound quality, spill-over (magnetic interference created by multiple hearing loops in close proximity), and costs of current systems.</p><p>Wireless technology exists now, and it can provide disabled users with the ability to participate in all aspects of life on more equal terms than previously possible.&nbsp;</p><hr><p>This article was first published on Nordic's&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>. </p>

People living with disabilities don't want special treatment; they want equal opportunity. The ability to act independently of, and at the same time connect with, others when moving, communicating, learning, working, and socializing.

Connected IoT tech promotes accessibility for all

<p id="isPasted">Despite specific industries experiencing slowdowns caused by the Covid-19 pandemic, projections in the Bluetooth technology market are optimistic through the remainder of 2021 and beyond.</p><p>Annual shipments of Bluetooth-enabled devices are expected to grow at a compound annual growth rate (CAGR) of 10 percent over the next five years, reaching 6.4 billion in 2025. More specifically, 70 percent of these shipments in 2025 will be peripheral devices such as earbuds, wearables, sensors, and smart lights – clearly outpacing platform-device shipments (for example, phones, tablets, and PCs) by three to one.</p><p>These forecasts headline the Bluetooth Special Interest Group's (SIG) 2021 <a href="https://www.bluetooth.com/bluetooth-resources/2021-bmu/" rel="noopener" target="_blank">Bluetooth® Market Update</a>, based primarily on analysis by ABI Research, which also points to an impressive upturn for different Bluetooth technologies across various verticals.</p><h2>Market shifts further towards Bluetooth LE</h2><p>Bluetooth Classic has peaked, and dual-mode devices (supporting both Bluetooth Classic and LE capabilities) are rising. Still, current trends suggest a marked increase in Bluetooth LE-only solutions. Shipments of these single-mode devices are expected to triple over the next five years, states the latest Bluetooth SIG report.</p><p>In particular, <a href="https://www.nordicsemi.com/Products/Bluetooth-Low-Energy?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">Bluetooth LE</a> will prove a dominant protocol among the global consumer electronic devices sector. The anticipation is that 96 percent of devices will include Bluetooth LE by 2025, primarily due to its prevalence in phones, tablets, and computers. A range of new features supported by Bluetooth LE also contributes to its forecast growth.</p><h2>Bluetooth LE Audio announces its arrival</h2><p>Over the past year, Bluetooth audio streaming has accounted for 1.3 billion shipments in 2021. The forecast for this solution area is to achieve 1.5 x growth from 2021 through 2025, reaching 1.7 billion annual shipments in 2025. Most of these shipments comprise headphones, with 633 million transported in 2021 alone. Demand for Bluetooth speakers will see shipments increase from 350 million in 2021 to 423 million in 2025.</p><p>But the launch of <a href="https://www.nordicsemi.com/Products/Bluetooth-LE-Audio?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">Bluetooth LE Audio</a> will take global Bluetooth audio to another level. Bluetooth LE Audio enhances Bluetooth Classic audio by providing higher quality audio streaming with longer battery life for speakers and headphones. And the prevalence of Bluetooth LE means Bluetooth LE Audio is likely to lead the way in audio streaming worldwide, with earbuds shipments alone forecast to see 3.4 x growth to 521 million by 2025.</p><p>Yet this is only the beginning of what Bluetooth LE Audio can make possible. The technology will include the Bluetooth Audio Sharing feature, enabling use cases where, for example, multiple headphones connect to a single audio stream. Bluetooth Audio Sharing might make public audio more accessible for the 1.5 billion people worldwide living with some form of hearing loss (figures from the World Health Organization). Utilized at conference centers, airports, and other public venues, it can form low-cost assistive listening systems by transmitting the audio stream directly to in-ear Bluetooth hearing assistance devices. More than 92 million such devices are expected to ship annually by 2024, according to Juniper Research.</p><p>Bluetooth LE Audio demands high-end processing capabilities. Nordic's <a href="https://www.nordicsemi.com/Products/nRF5340?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nRF5340 SoC</a> includes a new, flexible dual-processor hardware architecture with advanced security features designed to meet the Bluetooth LE multi-stream synchronized audio requirements.</p><h2>High-end processing supports advanced audio</h2><p>Bluetooth LE Audio is set to change the way we listen, but what drives the technology itself? Bluetooth LE Audio works through compressing the necessary data using an algorithm known as a Low Complexity Communication Codec (LC3) to reduce the throughput. Once received, another algorithm decompresses the data, allowing users to stream the same audio quality at reduced bitrates. This design also makes the creation of untethered earphones easier, as both can receive the stream with synchronized playback (through isochronous channels) instead of the old point-to-point stream.</p><h2>Bluetooth Location Services</h2><p>The Bluetooth Location Services market is also moving in the right direction. Expectations for the segment are to exhibit healthy medium-term expansion, with 32 percent CAGR in annual device shipments from 2021 to 2025.</p><p>According to the report, retail is the vertical taking the most significant advantage of Bluetooth Location Services, with 66 percent of all implementations currently supporting retail use cases. At the same time, 79 percent of Bluetooth Location Services solutions include indoor navigation properties. For example, 136 million Bluetooth RTLS tags and personal trackers will ship in 2021, the report claims, with 4 x growth in asset tracking tag shipments and 5 x growth in Bluetooth healthcare location services implementations predicted by 2025. The effects of the pandemic primarily spur the latter.</p><p>As wireless innovation continues in the face of recent challenges, resilient Bluetooth technology is powering its way into the future.</p><hr><p>This article was first published on Nordic's&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>. </p>

Despite specific industries experiencing slowdowns caused by the Covid-19 pandemic, projections in the Bluetooth technology market are optimistic through the remainder of 2021 and beyond.

Continued growth forecast for resilient Bluetooth and LE Audio technology

<p>USound currently offers two MEMS loudspeakers that are part of the Ganymede series: Adap UT-P2019 and Achelous UT-P2018. Adap is optimized towards maximum acceleration, making it ideal for free-field applications, whereas Achelous is optimized towards maximum excursion, making it especially suitable for occluded-ear applications. Therefore, USound MEMS loudspeakers can be evaluated in both acoustic domains: baffle and coupler conditions. For baffle conditions, the IEC 60268-5 standard is used, while for coupler conditions, the relevant standard is the IEC 60318-4, formerly known as 60711, or simply &ldquo;711&rdquo;. For both setups, proprietary measurement adapters are used to fit USound speakers to the standardized setup. Using the adapters, it is possible to achieve the results shown on the Adap and Achelous datasheets. Measurements with the Carme Box UJ-R1020 can also assess the speakers&rsquo; performance even if they lead to slightly different results. In this article, we will show several possibilities to perform the measurements and the differences between those methods.</p><h2 id="isPasted"><strong>BAFFLE MEASUREMENT (IEC&nbsp;60268-5)</strong></h2><p>To measure the loudspeaker in a<strong>&nbsp;</strong>baffle<strong>,</strong> it is necessary to place the MEMS speaker inside the measurement adapter. The following picture shows a drawing of the proprietary adapter used by&nbsp;USound.</p><figure><img data-fr-image-pasted="true" src="https://lh4.googleusercontent.com/J5XLouoWSuShn2kNsrXZlX7cw0jFZl5jQrjSL1EdbaFMATh5sfK1oVCd4B3D4nkMQWXAM0cgZFBTtXlW445rnkRFSDvZ_OB4v7qyiR53GGHtAIHN67NhwYzjFeitd6NnvWBOIlvs" alt="" class="fr-fic fr-dii"></figure><p>The electronic connection is achieved using pogo pins that press against the pads on the back of the loudspeaker. A gasket is placed in front of the speaker for sealing purposes, and an opening in the baffle enables the speaker to radiate towards the microphone, which is placed at a 10 cm distance from the baffle (as per the IEC 60268-5 standard). The SPL and THD results measured with this setup can be found on the&nbsp;<a href="https://www.usound.com/technical-documentation/" target="_blank">Adap UT-P2019&nbsp;datasheet</a>.</p><h3><strong>COUPLER MEASUREMENT (IEC&nbsp;60318-4)</strong></h3><p>For coupler measurements, a coupler adapter was designed to place the speaker close to the coupler without introducing additional resonances. This was obtained using a port of 3.6 mm diameter and 1.5 mm length (with an additional gasket of 0.5 mm, compressed to 0.3 mm). By using these dimensions, any emerging resonance is guaranteed to fall above the audible frequency range (&gt;20 kHz). With the use of USound&rsquo;s coupler adapter, the measurement can be performed without the earmold adapter. The SPL and THD results measured with this setup can be found on the&nbsp;<a href="https://www.usound.com/technical-documentation/" target="_blank">Achelous UT-P2018 datasheet.&nbsp;</a></p><h2>MEASURING MEMS SPEAKERS WITH THE CARME UJ-R1020 SPEAKER&nbsp;BOX.</h2><p>The two methods mentioned above require the use of proprietary coupler adapters. Another possibility to measure USound loudspeakers is by using the Carme UJ-R1020 speaker box. With a back volume of 100 mm&sup3;, it provides the necessary sealing to avoid an acoustic short circuit. It offers a convenient way to connect USound MEMS speakers to USound&lsquo;s linear amplifier Amalthea UA-R3010 or to the Helike UA-E3010 development board. With the Carme speaker box, both measurements in free-field and measurement on an artificial ear are&nbsp;possible.</p><h3><strong>MEASUREMENT WITH CARME BOX IN&nbsp;FREE-FIELD</strong></h3><figure><img data-fr-image-pasted="true" src="https://lh4.googleusercontent.com/U5uzyqnZLWRpXlwc1Gtv94bUBUlLcpX3s9UJe1VlHTHF_9lVpc0SFpNX6beQXZZ9-pAwYi3JtRSSDJryAP7TG87oB2c9DlVplTXJkcbf4DDb6Be2K3hJUxZLcoDwHzkSkSeDYsp0" alt="" class="fr-fic fr-dii"></figure><p>The box must be placed in a reflection-free space such as an anechoic chamber and pointed towards the microphone. Since no baffle is used in this setup and a back volume is introduced, the frequency response will be different from the results present on the Adap datasheet. Due to the missing baffle, the SPL will be ~6 dB lower below resonance frequency. The following graph compares the results obtained with the USound coupler adapter and with Carme&nbsp;Box.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-1024x409.png" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-1024x409.png 1024w, https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-300x120.png 300w, https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-768x307.png 768w, https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box-1536x614.png 1536w, https://www.usound.com/wp-content/uploads/2021/07/Adap-UT-P2019-SPL-measurement-in-the-Carme-speaker-box.png 2048w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="height: 300px;"><figcaption>Adap UT-P2019 SPL measurement in the Carme UJ-R1020 test box in free field</figcaption></figure><h4><strong>Measurement with Carme Box in a&nbsp;coupler</strong></h4><p>For coupler measurements, two setups are possible: with or without the earmould adapter. Therefore, the Carme UJ-R1020 box can be placed directly on the base part of the coupler or the earmould adapter, as shown in the following picture.&nbsp;</p><figure><img data-fr-image-pasted="true" src="https://lh4.googleusercontent.com/cW1VA3oRLSVzuCXuaaqTYz517VDH1PopwuEFtUNawEpoylpEmP7GkF3flRI7wmd1ptO-tgEIjBXap-lFYdmIcyO1_1njwZiwsStlFh9orP6DNuDWjewiBWte62oKzpxwD4WZtR2J" alt="" class="fr-fic fr-dii"></figure><figure><img data-fr-image-pasted="true" src="https://lh4.googleusercontent.com/iJ9Fsql8g_vE7FFd00DiJcy4zhFNG_TelJwJ5L79xjxKP_lA99pWIZ_1rv9uxcwK58lwGF_mtHWCZGEIgnG5L8MY-RKepYMYQ3ZzBQlYZcHrGkC6ZB5YCAKcELRQb6YyQ4DDF-Y1" alt="" class="fr-fic fr-dii"></figure><p>In both cases, to seal the air volume between the box and the coupler, it is necessary to apply sealing material (blu-tack, putty) between the two parts. Since the dimensions are not the same as with the USound coupler adapter, some differences will emerge.&nbsp;</p><p><strong id="isPasted">Recommended reading:&nbsp;</strong><span style="background-color: transparent;"><a href="https://www.wevolver.com/article/why-usound-mems-speakers-outperform-electrodynamic-and-balanced-armature-micro-speakers" rel="noopener noreferrer" target="_blank">Why USound MEMS speakers outperform electrodynamic and balanced armature micro speakers</a></span></p><p>Nevertheless, the results will also be relevant to assess the MEMS speaker&rsquo;s performance. A comparison between the results obtained from the two methods mentioned above and the setup with USound&rsquo;s coupler adapter is shown in the following graph.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/Achelous-UT-P2018-SPL-measurement-in-the-Carme-UJ-R1020.png" alt="Achelous UT-P2018 SPL measurement in the Carme UJ-R1020" srcset="https://www.usound.com/wp-content/uploads/2021/07/Achelous-UT-P2018-SPL-measurement-in-the-Carme-UJ-R1020.png 1003w, https://www.usound.com/wp-content/uploads/2021/07/Achelous-UT-P2018-SPL-measurement-in-the-Carme-UJ-R1020-300x124.png 300w, https://www.usound.com/wp-content/uploads/2021/07/Achelous-UT-P2018-SPL-measurement-in-the-Carme-UJ-R1020-768x316.png 768w" sizes="(max-width: 1003px) 100vw, 1003px" class="fr-fic fr-dii" style="height: 300px;"><figcaption>Achelous UT-P2018 SPL measurement in the Carme UJ-R1020 speaker-test box</figcaption></figure><p><br></p>

USound MEMS loudspeakers can be evaluated in both acoustic domains: baffle and coupler conditions. 

How to measure USound MEMS loudspeakers

<p id="isPasted">Most consumer electronics nowadays use traditional electrodynamic speakers. They consist of a magnet, a voice coil, a diaphragm and a support structure/enclosure. This working principle limits the minimum height that can be achieved with such a loudspeaker. The diaphragm’s suspension solely controls the mechanical behaviour, as electrodynamic microspeakers typically lack the centering spider of larger&nbsp;loudspeakers.</p><p>In this article we will demonstrate how MEMS-based microspeakers outperform the traditional voice coil-based microspeakers, and how manufacturers can benefit from a more reliable component to build more ergonomic and unique audio devices.&nbsp;</p><p>The trend in MEMS sensors and transducers is to replace the complete system with a silicone equivalent. While this is a viable solution for many applications, the physics of generating sound demands a more sensible approach. To generate sound, an important factor is the effective radiating area – the higher the area, the more sound is produced. Silicon processes scale inversely with size, however, and MEMS technology gets cheaper the smaller the silicon elements are. A second factor is the movement of the radiating area: The more the area moves, the more sound is being produced. With silicon being a stiff material with inherently high resonance frequencies, this works fine for ultrasonic applications but is difficult to apply towards audio&nbsp;frequencies.</p><p>USound’s innovation is to separate the radiating area and the driving elements into two components: the diaphragm and the MEMS motor. This allows to make the MEMS motor small, reaping all the cost benefits of smaller silicon elements while not sacrificing effective radiating surface area. It also allows optimization of the MEMS elements for force as opposed to large surface&nbsp;area.</p><p>Combining the advantages of semiconductor processes with larger surface areas is the reason why USound MEMS loudspeakers outperform other comparable concepts: the use of a diaphragm allows for smaller MEMS elements while retaining a larger acoustically effective area to produce&nbsp;sound.</p><p>Comparing MEMS speakers to traditional electrodynamic voice-coil or balanced armature loudspeakers, USound’s speakers are superior in three categories:</p><h3 id="isPasted">SYSTEM&nbsp;INTEGRATION</h3><p>Specific versions of USound MEMS loudspeakers can be used with reflow soldering. This allows integration into fully automated SMT assembly lines and many other&nbsp;environments.</p><p>MEMS loudspeakers are capacitive in nature, which means that the energy is not dissipated as heat. MEMS loudspeakers heat up significantly less than electrodynamic loudspeakers during use, which means that surrounding sensors are less&nbsp;affected.</p><h3>FORM&nbsp;FACTOR</h3><p>Silicon processes result in inherently thin systems. The MEMS motor in USound loudspeakers is less than half a millimeter thick, an order of magnitude thinner than electrodynamic loudspeakers. The fact that neither a heavy voice coil nor a heavy magnet are used results in a much lower weight of the loudspeaker as&nbsp;well.</p><p>The image below shows how much less space a MEMS loudspeaker (right) takes up compared to a traditional 6 mm dynamic loudspeaker (left) commonly used in modern TWS&nbsp;earbuds.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/03/USound-MEMS-speaker-solution-for-TWS-vs-voice-coil-solution-for-tws-2.png" alt="" class="fr-fic fr-dii" style="width: 500px;"></figure><h3>SOUND&nbsp;QUALITY</h3><p>Compared to voice-coil-base electrodynamic microspeakers, USound MEMS loudspeakers benefit from the stabilizing effect of the piezo motor, which not only provides the driving force but also acts similar to the centering spider of larger loudspeakers, keeping the movement more linear and controlled. The speed and precision of a linear actuator such as a MEMS piezo element are higher than a voice coil, which allows for&nbsp;<a href="https://www.usound.com/usounds-mems-speakers-extreme-bandwidth-technology/" target="_blank">higher bandwidth</a> and more accurate reproduction of high frequencies. At the same time, the bass can be tuned from linear (preferred by many audiophiles) to a significant boost (preferred by some people and anything in between. This means that a single MEMS loudspeaker can be used for the whole audible frequency range instead of using multiple&nbsp;speakers.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/03/USound-MEMS-speakers-Bass-boost.png" alt="" class="fr-fic fr-dii" style="width: 700px;"></figure>

In this article, we will demonstrate how MEMS-based microspeakers outperform the traditional voice coil-based microspeakers, and how manufacturers can benefit from a more reliable component to build more ergonomic and unique audio devices. 

Why USound MEMS speakers outperform electrodynamic and balanced armature micro speakers

<p id="isPasted">Most components in consumer electronics are silicon-based. The last component that is still manufactured traditionally is the loudspeaker — until now. USound is leading the revolution of the global speaker market, being the first company to introduce MEMS loudspeakers to the mass market. The thin form factor and wide bandwidth of USound MEMS speakers enable miniaturization of the audio module in wearables, hearables, smartphones, and smart devices in general. With traditional technology, this would be impossible without compromising the audio&nbsp;quality.</p><p>So what are the inherent advantages of USound MEMS loudspeakers compared to conventional electrodynamic and balanced armature&nbsp;speakers?</p><p><br></p><h3><strong>SMALLER&nbsp;SIZE</strong></h3><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/article.jpg" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/article.jpg 1024w, https://www.usound.com/wp-content/uploads/2021/07/article-300x132.jpg 300w, https://www.usound.com/wp-content/uploads/2021/07/article-768x338.jpg 768w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="width: 800px;"></figure><p>The main size advantage from USound MEMS loudspeakers comes from the thickness or lack thereof. In traditional electrodynamic loudspeakers, there is a lower limit to the size of the voice coil and magnet assembly. And while rare-earth magnets (especially neodymium magnets) allow the use of smaller magnets while retaining the same sound pressure level output, they still dominate the geometry and impose a lower limit to the size of the loudspeaker. Simply put: traditional microspeakers consist mostly of the magnet. They can not be miniaturized further, as the magnet can not shrink without losing sound&nbsp;output.</p><p>Replacing the voice coil + magnet assembly with a MEMS motor removes this limit. The thickness of a MEMS motor is essentially zero compared to a coil + magnet. In the case of MEMS loudspeakers, the loudspeaker thickness is limited only by how far the motor needs to excurse. This allows USound MEMS loudspeakers to be as thin as 1.3&nbsp;millimeters.</p><p>This reduced thickness frees up more real estate for other components, such&nbsp;as</p><ul><li>A larger battery (higher battery life)</li><li>Accelerometers (headtracking)</li><li>Additional microphones (beamforming, noise cancelling)</li><li>UHF sensor (“find my device”)</li><li>Infrared-sensors (ear detection)</li><li>Pulse-oximeter (health sensoring)</li></ul><p><br></p><h3>PCB-BASED</h3><p>Since USound MEMS loudspeakers are PCB-based, they can easily be combined with additional SMD components to form an audio module. They can be mounted to a PCB via reflow soldering or conductive glue. This allows for easy outsourcing of acoustic design, rapid prototyping, and evaluation and, thus, a faster time to market.&nbsp;</p><p><br></p><h3>NON-FERROMAGNETIC&nbsp;MATERIALS</h3><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/MEMS-speakers-1.jpg" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/MEMS-speakers-1.jpg 1024w, https://www.usound.com/wp-content/uploads/2021/07/MEMS-speakers-1-300x103.jpg 300w, https://www.usound.com/wp-content/uploads/2021/07/MEMS-speakers-1-768x263.jpg 768w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="width: 800px;"></figure><p>On request, USound MEMS speakers can be manufactured without ferromagnetic materials with zero tradeoffs in acoustic performance. This allows the use of these loudspeakers in areas with strong magnetic fields, i.e., to communicate with the patient inside an MRI&nbsp;machine.</p><p><br></p><h3><strong>SMALLER MOVING MASS, THEREFORE LOWER&nbsp;VIBRATIONS</strong></h3><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/article3.jpg" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/article3.jpg 1024w, https://www.usound.com/wp-content/uploads/2021/07/article3-300x132.jpg 300w, https://www.usound.com/wp-content/uploads/2021/07/article3-768x338.jpg 768w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="width: 800px;"></figure><p>Ideally, the only part of the loudspeaker that moves should be the diaphragm; if the ratio of diaphragm mass vs. total mass is too high, the casing of the loudspeaker will vibrate as well. These unwanted mechanical vibrations can cause solid-borne sound to enter microphones in the immediate vicinity. If the signal of these microphones is used to feed the loudspeaker (e.g., in an earphone in transparency mode or in a hearing aid), this will cause a feedback loop, typically audible as a highly irritating, screeching sound. Due to the absence of a heavy voice coil, USound MEMS speakers are much lighter and produce significantly fewer mechanical vibrations. This is important not only for hearing aids but also for modern TWS earphones with “transparency”/”hearthrough” mode, where the recording of the microphone is being played through the loudspeaker on the same&nbsp;device.</p><p><br></p><h3>NO ELECTROMAGNETIC&nbsp;RADIATION</h3><p>Conventional speakers rely on the Lorentz force, where a change in the electric field, by applying a voltage to the coil while it is suspended in a magnetic field, imposes a force on said coil and causes it to move. The induced change in the electromagnetic field is a form of electromagnetic radiation, which will radiate into the surrounding. Some types of sensors can easily be disturbed by this unwanted electromagnetic pollution. USound MEMS loudspeakers, on the other hand, rely on the piezoelectric principle, which causes no electromagnetic radiation. This eliminates the need for any magnetic shielding in mobile devices between speakers and other sensitive parts (like&nbsp;sensors).</p><p><br></p><h3>NO HEAT&nbsp;GENERATION</h3><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/07/low-heat-generation-2.jpg" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/07/low-heat-generation-2.jpg 1024w, https://www.usound.com/wp-content/uploads/2021/07/low-heat-generation-2-300x103.jpg 300w, https://www.usound.com/wp-content/uploads/2021/07/low-heat-generation-2-768x263.jpg 768w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="width: 800px;"></figure><p>While the electric impedance of conventional microspeakers has a reactive component caused by the coil, the impedance of the whole system is normally dominated by the resistive component of the length of wire that forms said coil. This means that the electrical energy is mostly converted into thermal energy as it dissipates across the ohmic resistance. In typical mobile phone speakers, the coil heats up to over 70&nbsp;°C.</p><p>However, in USound MEMS loudspeakers, the electric impedance is determined solely by the capacity between the two electrodes of the MEMS element. The impedance is therefore purely capacitive and has virtually no resistive component, meaning that the energy does not dissipate, and a much smaller percentage is converted to thermal energy. This means that less heat is generated. Typically the temperature of the hottest part of a USound MEMS loudspeaker is not significantly above room temperature. Like the reduced EMI, this causes less disturbance for surrounding sensors (especially infrared sensors) and also reduces the wear and tear of other components that are sensitive to temperature (e.g., batteries). The electric impedance being purely capacitive also means that the electric energy can be “reused” by pulling it back out of the loudspeaker, so to speak. This lowers the total power consumption of the&nbsp;loudspeaker.</p><p><br></p><h3>SUMMARY</h3><p>USound MEMS loudspeakers offer many benefits over conventional&nbsp;loudspeakers.</p><ul><li>Smaller size</li><li>Easier integration</li><li>Easier modularization</li><li>Direct PCB mounting</li><li>No ferromagnetic materials</li><li>Less unwanted vibrations</li><li>No EMI</li><li>No heat generation</li></ul><p>And all these benefits come while still fulfilling the requirements for audio performance. There is no need to make a tradeoff in the actual sound — but you can now build high-end audio products with additional functionalities.</p>

Most components in consumer electronics are silicon-based. The last component that is still manufactured traditionally is the loudspeaker — until now.  Loudspeakers using USound MEMS technology offer a multitude of inherent advantages, compared to traditional ED or BA speakers.

Inherent characteristics of USound MEMS speakers

<p id="isPasted">When we discuss what makes a headphone or earphone sound “good” and “bad”, we inevitably need to ask the question, well how should a headphone&nbsp;sound?</p><p>Is there an objective way to answer this? Or does it all depend on personal&nbsp;preference?</p><p>The truth, as so often, is somewhere in the&nbsp;middle.</p><p>The first question we need to answer is: “<strong>what should a speaker sound&nbsp;like?</strong>”&nbsp;</p><p>The short answer is (after decades of&nbsp;research):</p><ol><li>A speaker should produce a flat frequency response in an anechoic room.&nbsp;</li><li>The loudspeaker should be designed such that its directivity (how the sound is radiated to directions other than to the front) makes it so that when the same speaker is placed in a “normal” (slightly reverberant) room, the frequency response will be a little tilted – about 4 dB more bass, and about 2 dB less treble.</li></ol><p>The debate about this is&nbsp;<em>basically</em> over, the&nbsp;<a href="https://books.google.at/books/about/Sound_Reproduction.html?id=sGmz0yONYFcC&redir_esc=y" target="_blank">question has been answered</a>, and indeed, virtually all “good” speakers show this behavior (flat on-axis, controlled sound power&nbsp;output).</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/04/room-target-curves-1024x683.png" alt="" srcset="https://www.usound.com/wp-content/uploads/2021/04/room-target-curves-1024x683.png 1024w, https://www.usound.com/wp-content/uploads/2021/04/room-target-curves-300x200.png 300w, https://www.usound.com/wp-content/uploads/2021/04/room-target-curves-768x512.png 768w, https://www.usound.com/wp-content/uploads/2021/04/room-target-curves.png 1200w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="height: 480px;"></figure><p>And since recording studios use good speakers (studio monitors) to record, monitor, and mix the music that consumers listen to later, it makes intuitive sense to listen to the music on similarly performing speakers – because that is what the music is supposed to sound like, this is what the artist and recording engineers decided “sounded good”. So the&nbsp;<em>target</em> for speakers is Flat on-axis, controlled sound power output (smooth&nbsp;directivity).</p><p>Now, the same question can be asked for headphones: “<strong>what should a headphone sound like?</strong>” (in terms of: What is the ideal frequency response of a headphone”), and the short answer is: “it’s not that&nbsp;simple”.</p><p>The answer is simple for speakers (not that simple really, but it has been answered), but for headphones, it is much more&nbsp;difficult.</p><p>The first difficulty is “how do you measure it?”. It’s easy with speakers – put a calibrated microphone at a standardized distance, in a standardized room (e.g. anechoic). With headphones, this isn’t possible, because much of the sound depends on the shape of the head. The general consensus is to measure headphones on artificial heads, with artificial ears and artificial ear canals. The problem with this is, that head shape, ear shape, and ear canal has a significant influence on the acoustics, most prominently a 10-20 dB boost in the upper midrange / treble part of the spectrum, depending on the angle of&nbsp;incidence:</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/04/ear-resonance-1024x683.png" alt="Influences on measured ear resonance" srcset="https://www.usound.com/wp-content/uploads/2021/04/ear-resonance-1024x683.png 1024w, https://www.usound.com/wp-content/uploads/2021/04/ear-resonance-300x200.png 300w, https://www.usound.com/wp-content/uploads/2021/04/ear-resonance-768x512.png 768w, https://www.usound.com/wp-content/uploads/2021/04/ear-resonance.png 1200w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="height: 480px;"></figure><p>The important thing is: We “hear” this boost even when listening to speakers – because our ears are&nbsp;<em>always</em> there. When the artificial head measurement shows a high boost at 3 kHz, this sounds “flat, linear” to us, because this is what our ears hear. But how should this boost look exactly? What is the&nbsp;<em>target frequency&nbsp;response</em>?</p><p>Enter a scientist named Sean Olive. His hypothesis was that the best way to come up with a target response for headphones was to place a pair of good speakers in a “regular” listening room similar to the control rooms of recording and mixing studios, and measuring the frequency response with an artificial head setup. Harman’s&nbsp;<a href="ttps://www.aes.org/e-lib/browse.cfm?elib=14873" target="_blank">reference listening room</a> is neither fully reverberant nor fully anechoic, it features a reverberation time of about 0.4 seconds, very similar to what professional recording and mixing studios&nbsp;use.</p><p>Now if we measure a headphone using that same artificial head and the headphone was to have the same frequency response that we previously measured in the room, then this frequency response would be ideal, or so Sean Olive proposed. And further research proved that&nbsp;<a href="https://www.aes.org/e-lib/browse.cfm?elib=16768" target="_blank">he was right</a>, the majority of both trained and untrained listeners prefer this target curve over any other target&nbsp;curve.</p><p>This allows us to escape the circle of confusion, and get closer to the ideal of hearing the same thing the artists, producers and engineers heard when creating the music that we listen to. But the topic does not end&nbsp;here!</p><p>It’s important to understand that the result of this research is – contrary to popular belief – is not a single fixed frequency response curve that needs to be followed to the letter. In fact, the research confirmed what listeners had suspected for quite some time: The preferred amount of bass varies from person to&nbsp;person.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/04/bass-variation2-1024x683.png" alt="Preferred bass-response on in-ear headphones" srcset="https://www.usound.com/wp-content/uploads/2021/04/bass-variation2-1024x683.png 1024w, https://www.usound.com/wp-content/uploads/2021/04/bass-variation2-300x200.png 300w, https://www.usound.com/wp-content/uploads/2021/04/bass-variation2-768x512.png 768w, https://www.usound.com/wp-content/uploads/2021/04/bass-variation2.png 1200w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="height: 480px;"></figure><p>Additional research performed by&nbsp;<a href="https://iem.kug.ac.at/institut-fuer-elektronische-musik-und-akustik-iem.html" target="_blank">USound and IEM</a> showed that in the presence of background noise (such as distant traffic), listeners tend to prefer more bass and slightly less treble compared to the original Harman&nbsp;Target.</p><p>For this reason, USound’s USOUND1V1 reference target was tuned by expert listeners to contain more bass energy below 300 Hz, at the same time exhibiting a more smooth and timbrally accurate reproduction of the upper midrange and treble response. This results in a warm and punchy sound without sacrificing clarity, which maintains the original timbre of&nbsp;voices.</p><figure><img data-fr-image-pasted="true" src="https://www.usound.com/wp-content/uploads/2021/04/target-curve-comparison2-1-1024x683.png" alt="Comparison of target frequency response curve." srcset="https://www.usound.com/wp-content/uploads/2021/04/target-curve-comparison2-1-1024x683.png 1024w, https://www.usound.com/wp-content/uploads/2021/04/target-curve-comparison2-1-300x200.png 300w, https://www.usound.com/wp-content/uploads/2021/04/target-curve-comparison2-1-768x512.png 768w, https://www.usound.com/wp-content/uploads/2021/04/target-curve-comparison2-1.png 1200w" sizes="(max-width: 1024px) 100vw, 1024px" class="fr-fic fr-dii" style="height: 480px;"></figure><p>The predictable and&nbsp;<a href="https://www.usound.com/usounds-mems-speakers-extreme-bandwidth-technology/" target="_blank">highly precise performance of MEMS loudspeakers</a> enables more accurate tuning with digital filters. The precision of the MEMS actuators makes them the ideal transducer for an acoustically optimized system and allows using more natural-sounding filters to achieve the target sound.</p>

Talking about target curves

How earphones should sound

<p dir="ltr"><em>This article was co-authored by Raj Senguttuvan and Vikram Shrivastava.&nbsp;</em>&nbsp;</p><h1 dir="ltr">Introduction</h1><p dir="ltr">The last decade, but particularly 2020, saw a massive increase in video calling and engagement with voice-enabled devices primarily through the work-from-home trend created by the pandemic. However, our use of video calls isn&rsquo;t restricted to just work Zoom meetings. We are now using video calling for teaching, exercise classes, to experience live music, as a tool for interacting at conferences, and <a href="https://www.eatwith.com/" target="_blank">even to go to restaurants.</a> This virtual engagement occurs via laptops, smartphones, tablets, and other IoT devices such as Amazon Echo Show, Facebook Portal, Peloton, <a href="https://imp.i277339.net/c/1141873/823006/11505?u=https%3A%2F%2Ftempo.fit%2Fpdp%2Ftempo-studio&subId2=[]st[p]cjv2u8o050017o5yeyn1o93c5[i]H2ac18[t]w[r]google.com[d]D[z]m" target="_blank">Tempo Studio</a>, etc. We have also embraced the use of voice-controlled devices such as home assistants and wireless earphones, and other smart home applications.&nbsp;</p><p dir="ltr">The core point that limits enjoyable and engaging interactive audio, video call, or home assistant experiences is consistent sound quality in the presence of noise and other distractors. The ability of your device to intelligently manage sound is what makes or breaks your ability to communicate.&nbsp;</p><h2 dir="ltr">Increasing audio expectations</h2><p dir="ltr">Dubbed &lsquo;smart sound&rsquo; by product makers, audio intelligence is the ability of a device to process sound to deliver the best user experience. As the increase in voice-led device use for communication, entertainment, and health management increases, so does the demand for a seamless, low-barrier experience with increased functionality. Users now expect devices to understand more than simple wake or keywords (such as Alexa) and seek the ability to move between devices and applications with superior sound quality to enable an immersive and seamless experience, whether for professional conferencing or personal entertainment.&nbsp;</p><p dir="ltr">Devices should be able to combine your voice and/or voice command with your personal preferences and environmental data to adapt sound processing to your specific context. This is known as contextual awareness.&nbsp;</p><h1 dir="ltr">What is Contextual Awareness?</h1><p dir="ltr">Contextual-aware devices combine user-specific information, such as location, preferences, and ambient sensor data, to better understand what the user is asking for and more accurately execute functions in response to a certain command or trigger.&nbsp;</p><p dir="ltr">Always-listening devices use signal processing technology combined with <a data-lf-fd-inspected-kn9eq4roawkarlvp="true" href="https://mediatum.ub.tum.de/doc/1463108/document.pdf" rel="noopener noreferrer" target="_blank">machine learning</a> to differentiate between sound types such as natural sounds, voices, background interference, etc. These sounds are often divided into &ldquo;scenes&#39;&#39; and &ldquo;events&rdquo;. A scene is the users setting such as a noisy airport terminal or a quiet working space. The events are someone speaking, a glass breaking, or a dog barking. A context-aware device can process these groups of sounds to ensure the intent of the action, whether it is a video call or a voice command, and is processed for optimal experience.&nbsp;</p><p dir="ltr"><br></p><div class="fr-img-space-wrap"><span class="fr-img-caption fr-fic fr-dib" style="width: 788px;"><span class="fr-img-wrap"><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjE0NzkxMjg1ODE2LUlNQUdFIDQ2LTAxLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 788px;" class="fr-fic fr-dib"><span class="fr-inner" spellcheck="false">Figure 1: Context-aware system schematic.</span></span></span><p class="fr-img-space-wrap2">&nbsp;Dedicated audio edge processors with a focus on audio fidelity and with machine learning optimized cores are the key to contextually aware and high-quality audio communication devices. These processors can deliver enough compute power to process complex audio using just a small percentage of the energy of a generic Digital Signal Processing (DSP) implementation. These audio edge processors use ML algorithms for superior sound processing in addition to providing a &nbsp;more contextual audio experience.&nbsp;</p></div><p><br></p><h2 dir="ltr">&ldquo;I think you are on mute&rdquo;</h2><p dir="ltr">Video conference calls have been a focal point in 2020 and continue to dominate work and social lives in 2021. The gaps in technology are revealed quickly when devices, people, and environments fail to keep up with the demands of the calls - to the point where the phrase &lsquo;I think you&#39;re on mute&rsquo; was dubbed the<a href="https://www.humanresourcesonline.net/the-most-used-business-phrases-of-2020-i-think-you-re-on-mute" rel="noopener noreferrer" target="_blank">&nbsp;most used business term</a> in 2020. Dedicated audio processors with ML is the necessary approach to solve some of the common video conferencing pain points.&nbsp;</p><p dir="ltr">ML on dedicated audio processors are already addressing some common video conference pain points:</p><ul><li dir="ltr"><strong>Selective noise canceling</strong>. By understanding a range of scenes and action noises, certain background elements such as a fan, heater, or street noise can be removed, thereby, improving overall call quality and the ability to work in a wider variety of environments.&nbsp;</li><li dir="ltr"><strong>Hi-fi audio reconstruction.</strong> Analogous to the way budget smartphones use smart software to increase the image quality from low-quality cameras, ML in real-time audio processing can improve the audio quality from low-quality microphones.&nbsp;</li><li dir="ltr"><strong>Spatial audio for improved user experience.</strong> Already available on advanced gaming headphones and some TWS devices, advanced digital sound optimization techniques provide users a spatial audio experience. Spatial audio can create a natural listening experience for the user, which can help mitigate &ldquo;<a href="https://news.stanford.edu/2021/02/23/four-causes-zoom-fatigue-solutions/" target="_blank">Zoom Fatigue</a>&rdquo;.</li></ul><p dir="ltr">In the future, ML on audio processors will have even more advanced capabilities such as real-time speech processing that would enable automatic language translations. Additionally, ML can solve the &lsquo;on mute&rsquo; problem by becoming more aware of the user&rsquo;s context and offer prompts to unmute.</p><h1 dir="ltr">A look at specialized audio edge processors</h1><p dir="ltr">There are several areas audio edge processors get right to deliver exceptional audio and voice command experiences.&nbsp;</p><h2 dir="ltr">Noise and Distance</h2><p dir="ltr">Beamforming is the process where the device can engage its ability to focus the listening or output sound in a particular direction. Noise suppression makes conversations in everyday scenarios possible. A listening device determines the direction(s) of the voice source(s) and that of noise sources. ML classification techniques are then used to determine which beams have voice or noise in them. &nbsp;The DSP then focuses on beams with voice content only for further voice UI processing. For example, in a conferencing system, the device must identify the direction of arrival of sound, and multiple speakers must be tracked at all times in a 360-degree fashion. Noise sources can also be classified further for audio event detection like glass break, fire alarms, and gunshots, etc for further expanding the role into audio aware smart home systems.&nbsp;</p><p dir="ltr">Proximity detection is also essential for dynamic listening and speaking experience. &nbsp;The device detects user proximity to the microphone and adjusts the microphone&rsquo;s gain. This feature enables active video conferencing for presentations, workouts, and learning environments. These features are central to the design of advanced video conferencing devices such as the new Amazon Show which features a screen that rotates to where it senses the user.&nbsp;</p><p><span class="fr-video fr-deletable fr-fvc fr-dvb fr-draggable" contenteditable="false" draggable="true"><iframe src="https://www.youtube.com/embed/fxUSSgrHL-o?&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" style="width: 789px; height: 504px;" data-gtm-yt-inspected-8="true" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe></span></p><h2 dir="ltr">Latency</h2><p dir="ltr">Humans can <a href="https://towardsdatascience.com/real-time-noise-suppression-using-deep-learning-38719819e051" rel="noopener noreferrer" target="_blank">generally tolerate</a> up to 200ms of end-to-end latency on a call before we begin to talk over each other. Low latency processing in edge processors is, therefore, a critical requirement for ensuring high-quality voice communication.</p><h2 dir="ltr">Power consumption</h2><p dir="ltr">Audio edge processors designed with proprietary architectures, hardware accelerators, and special instruction sets can optimally run audio and ML algorithms. These optimizations help with reducing power consumption in audio-heavy use cases such as video conferencing.</p><h2 dir="ltr">Integration</h2><p dir="ltr">Audio edge processors that open up their architectures and development environments accelerate innovation by providing audio application developers the tools and support to create new devices and applications. Future audio devices will be a collaborative effort.</p><h2 dir="ltr">Security</h2><p dir="ltr">Edge processing can minimize the need for cloud processing providing many benefits, including increased data security. For example, most consumers are not comfortable with data from personal smart home devices being transferred continuously to the cloud for processing. These fears have proven true with several <a href="https://www.theguardian.com/technology/2020/dec/23/amazon-ring-camera-hack-lawsuit-threats" target="_blank">major breaches</a> by leading device manufacturers in the last years. Peace of mind can be achieved when personal data is processed for analysis or inference at the device. An excellent example of this is a smart home security device that has been trained to hear certain event sounds, such as glass breaking, that act as a trigger to alert the homeowner. As the processing of the sound and the alert occurs on the device, it does not need to be in continuous connection to the cloud, which enhances the security of the system.</p><h1 dir="ltr">Delivering Audio Intelligence at the Edge</h1><p dir="ltr"><a href="https://www.knowles.com/products/audio-processors" target="_blank">Knowles AISonic&trade; IA8201: Dual Core</a> is an audio edge processor specifically designed for advanced audio and machine learning applications, enabling power-efficient intelligence and privacy at the edge. It offers robust voice activation and multi-microphone audio processing with sufficient compute power to perform advanced voice processing and audio output, context awareness, and gesture control for today&rsquo;s most advanced consumer electronics. Processing voice and audio voice with an audio edge processor like IA8201 can keep the power-hungry host processor off as long as possible to extend battery life. &nbsp;</p><p dir="ltr">In addition, it also enables new use cases for enhanced user experience by having the capability to run ML algorithms on multiple sensor inputs to deliver a more natural and contextual user experience.</p><p dir="ltr">Audio edge processors like IA8201 have a place in a variety of audio and voice-enabled applications including smart speakers, video conferencing devices, tablets, Bluetooth headphones, and smart home devices.</p><p dir="ltr"><strong id="isPasted">Recommended reading:&nbsp;</strong><span style="background-color: transparent;"><a href="https://www.wevolver.com/article/enhancing-the-utility-of-audio-ai-in-everyday-devices-using-audio-source-classification" rel="noopener noreferrer" target="_blank">Enhancing the utility of Audio AI in everyday devices using Audio Source Classification</a></span></p><h1 dir="ltr">Conclusion</h1><p dir="ltr">Dedicated audio edge processors will define the next generation of audio and voice-enabled devices creating more context-aware, immersive, and seamless audio communication experiences. Their ability to enable efficient processing for low power and low latency voice communications, noise reduction, context awareness, and accelerated ML inferencing of sensor inputs opens the possibilities to an explosion of new user experiences for the human-machine interfaces.&nbsp;</p><hr><h1><em>References and further reading:</em><a href="https://blog.adobe.com/en/publish/2019/04/09/contextual-ai-the-next-frontier-of-artificial-intelligence.html#gs.tuw2rt" target="_blank"></a></h1><p><a href="https://blog.adobe.com/en/publish/2019/04/09/contextual-ai-the-next-frontier-of-artificial-intelligence.html#gs.tuw2rt" target="_blank">https://blog.adobe.com/en/publish/2019/04/09/contextual-ai-the-next-frontier-of-artificial-intelligence.html#gs.tuw2rt</a></p><p dir="ltr">Antonini, Mattia &amp; Vecchio, Massimo &amp; Antonelli, Fabio &amp; Ducange, Pietro &amp; Perera, Charith. (2018). Smart Audio Sensors in the Internet of Things Edge for Anomaly Detection. IEEE Access. PP. 1-1. 10.1109/ACCESS.2018.2877523.&nbsp;</p><p dir="ltr">Do, Ha &amp; Sheng, Weihua &amp; Liu, Meiqin &amp; Zhang, Senlin. (2016). Context-aware sound event recognition for home service robots. 739-744. 10.1109/COASE.2016.7743476.&nbsp;</p><p dir="ltr"><a data-lf-fd-inspected-kn9eq4roawkarlvp="true" href="https://www.knowles.com/docs/default-source/default-document-library/knowles-ia8201-product-brief-final1b6a11c731dff6ddbb37cff0000940c19.pdf" target="_blank">https://www.knowles.com/docs/default-source/default-document-library/knowles-ia8201-product-brief-final1b6a11c731dff6ddbb37cff0000940c19.pdf</a></p><p dir="ltr"><a href="https://voicebot.ai/2019/06/01/dedicated-audio-processors-at-the-edge-are-the-future-here-are-the-reasons-why/" target="_blank">https://voicebot.ai/2019/06/01/dedicated-audio-processors-at-the-edge-are-the-future-here-are-the-reasons-why/</a></p><p dir="ltr"><a href="https://www.networkworld.com/article/3262105/how-edge-computing-makes-voice-assistants-faster-and-more-powerful.html" target="_blank">https://www.networkworld.com/article/3262105/how-edge-computing-makes-voice-assistants-faster-and-more-powerful.html</a></p>

Dedicated audio edge processors with machine learning will deliver increasingly natural communication experiences.

Audio edge processors deliver sublime context-aware communication experiences

<p>The invention of Thomas Edison’s phonograph—which used a needle to etch a groove, which could then be played back by another needle following the groove’s indentations—heralded the era of recorded sound.</p><p>Those grooves, first on wax with mechanical playback and then on vinyl with electrical playback, continued as the mainstay of recorded sound until after the second world war. Then the German invention of magnetic tape became the preferred media for original recordings. Tape lasted until the mid-70s when the analoge era was brushed aside by digital recording using technology pioneered by Sony.</p><p>Today, the benchmark for high-quality digital sound is the CD. CD-quality digital technology samples analoge sound at 44.1 kHz with 16-bit precision (1.41 Mbps), a sampling rate sufficient to capture all the sounds humans can hear across the 20 kHz bandwidth of the ear. Such a rich stream of data currently demands a wired circuit to reproduce robustly, but wireless tech is rapidly catching up.</p><h2>Higher quality wireless audio with extended battery life</h2><p>Back in January 2020, the Bluetooth Special Interest Group (SIG) announced work had started on a specification for LE Audio. Hailed as “the next generation” of Bluetooth audio, the organization claimed the new technology—which will support wireless audio streaming over Bluetooth LE—will bring higher quality sound and extended battery life from speakers and headphones.</p><p>LE Audio also brings other new functionality, including multi-stream synchronized audio for applications such as earbuds, and Audio Sharing, whereby a single audio source can be broadcast to multiple recipients.</p><p>A key technical element of LE Audio, LE Isochronous Channels, was introduced as part of Bluetooth 5.2. The feature addresses a key drawback of Classic Audio by providing a mechanism that ensures multiple sink devices receiving data from the same source reproduce it simultaneously.</p><h2>LC3 provides another key part of the LE Audio specification</h2><p>A significant step towards LE Audio has just come with the Bluetooth SIG’s release of the specification detailing the Low Complexity Communications Codec (LC3). A codec is an algorithm that compresses digital data to reduce the throughput of a wireless link, while a companion algorithm decompresses the data at the other end.</p><p>LC3 is an efficient Bluetooth audio codec for use in LE Audio applications. It can encode speech and music at various bitrates by supporting sampling rates of 8, 16, 24, 32, 44.1, and 48 kHz and sample resolutions of 16, 24, and 32-bits. Bit rate flexibility allows developers to trade-off sound quality against power consumption and, in turn, extend battery life or reduce battery size.</p><p>LC3 is not the first codec the Bluetooth SIG has unveiled. In 2003, Classic Audio was accompanied by a low-complexity sub-band codec (SBC) designed to boost audio quality at low-to-medium bit rates. Although SBC was moderately successful, proprietary and manufacturer-defined codecs, such as Qualcomm’s aptX and aptX-HD, and Sony’s LDAC, also work well with Classic Bluetooth Audio.</p><p>However, according to the Bluetooth SIG, extensive listening tests have shown that LC3 provides improvements in audio quality over SBC, with the most notable improvements occurring at low data rates. Get Connected Blog readers can check out the audible difference between LC3 and SBC by heading to an interactive listening demo on the Bluetooth website.</p><h2>Nordic SoC support for LE Audio</h2><p>With good timing, Nordic is now offering its <a href="https://www.nordicsemi.com/Products/Low-power-short-range-wireless/nRF5340?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">nRF5340 SoC</a> in <a href="https://www.nordicsemi.com/News/2020/12/nRF5340-is-now-available-as-a-production-version-through-Nordics-distribution-network?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">production volumes</a> together with a production version of the SoC’s <a href="https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF5340-DK?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">development kit</a> and <a href="https://www.nordicsemi.com/Software-and-tools/Software/nRF-Connect-SDK?utm_campaign=2021%20wevolver" rel="noopener noreferrer" target="_blank">software development tools</a>. The nRF5340 combines a high-performance application processor with a fully-programmable network processor, plus advanced root-of-trust and trusted execution security features. With an LE Audio-enabled software stack, the nRF5340’s radio supports LE Isochronous Channels, and LC3 runs efficiently on the SoC. The nRF5340 also has an on-chip audio PLL for audio synchronization for true wireless stereo playback.</p><hr><p>This article was first published on Nordic's&nbsp;<a href="https://blog.nordicsemi.com/getconnected" rel="nofollow" target="_blank"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>. </p>

The Bluetooth SIG unveils the codec that will help power LE Audio’s enhanced sound.

One step closer to Bluetooth LE Audio

<p>EPFL’s Laboratory for Experimental Museology (eM+), led by Sarah Kenderdine, has received support from Engagement Migros to produce muse, a pioneering audience evaluation app, in collaboration with over 20 Swiss museums. The tool provides visitors with an engaging way to communicate their experiences, while helping museums to consider this feedback when developing exhibits and other attractions. </p><p>Encouraging audiences to participate in evaluations in large enough numbers to provide useful data is notoriously difficult, and for good reason: respondents may find the process time-consuming or boring. But what if you were invited to communicate your experience at a museum exhibit by making drawings, leaving voice recordings, interacting with animated graphics, or taking photos?&nbsp;</p><p>This is the aim of muse: a design-led audience evaluation app that helps museums get to know their visitors better. In addition to geographic and demographic information, the tablet-based tool uses some 30 interactive elements to collect qualitative, subjective data about museum visitors’ experiences.</p><h2><strong>Capturing experiences</strong></h2><p>Sarah Kenderdine leads the eM+ lab in EPFL’s College of Humanities. She explains that in Switzerland, as in many parts of the world, museums usually collect only basic demographic data from their visitors, such as number of entries and origin. The goal of muse is therefore to give museums access to data analytics tools that can help them focus on many visitors as individuals, and to use the quality of visitor engagement as a method to define, measure, and program for improved museum experiences.<br><br>“It is the social, political, emotional, educational, and creative elements, in addition to how deeply people are participating in a museum’s programs and exhibitions, that should be the basis for measuring value,” Kenderdine says.<br><br>Unlike a traditional audience evaluation or survey, visitors use muse to record their experiences as they pass through an exhibit, rather than afterward.<br><br>“Muse is always meant to be deployed inside the space of experience, and not afterward, so people can reflect in real time on what their reactions to it really are. Simultaneously, museum staff can see aggregated results on a real-time dashboard,” says Kenderdine, who has been developing muse since 2012.<br><br>She notes a recent example of the success of the muse model, when a previous version of the app was deployed for the Winter at Tantora arts festival in AlUla, Saudi Arabia. It engaged 6,000 respondents across five surveys with 120 data points, resulting in 1,200 pages of reports.<br><br>“This data provided a phenomenal insight into customer loyalty, future planning, and creative responses to the cultural offering at this new world heritage destination.”<br><br>With the support of Engagement Migros, and the participation of more than 20 museums across Switzerland, Kenderdine’s goal now is to bring muse to the next level, including more sophisticated analysis driving better public outcomes for museums and their audiences. The project will be officially launched on September 17th, 2020 at EPFL’s ArtLab.</p><h2><strong>Looking ahead</strong></h2><p>At first, the muse team will partner with eight ‘core’ museums and institutions for a three-year period, including: the Château de Morges (Morges), the Haus der Elektronischen Künste (Basel), the International Red Cross Museum (Geneva), the Musée d'Éthnographie (Geneva), the Museum für Gestaltung (Zürich), the Rietberg Museum (Zürich), and the Olympic Museum (Lausanne). Each institution will be supported by an administration portal for creating questions and surveys, an app for collecting data, and a dashboard for visualizing the data in real time. A further 16 museums will be invited to join the project through an open call starting in late 2020.<br><br>Throughout the four-year funding period, the muse team will develop convincing case studies for the Swiss museum landscape. It will also explore options for commercializing the app and its licensing models, and for expanding to include all cultural offerings across Europe and beyond – all in close collaboration with its partners.<br><br>“With its user-centric approach, muse supports museums in their efforts to continue being active places in society,” says Johanna Muther, Project Manager at Engagement Migros.<br><br>Kenderdine adds that going forward, muse will also help museums to increasingly embrace their audiences with renewed attention as they adapt to the challenges of the coronavirus pandemic. “Visitors are active participants, and not just consumers, in helping to support museums as polyvocal places. Muse gives an amplifier to those voices,” she says.</p><hr><p><strong>About muse</strong><br>Muse is the voice of the visitor. In addition to quantitative data, such as geographic and demographic information, the tool can also be used to collect qualitative findings on the direct impact of an exhibition visit. The focus of the app is on creating playful interactions, and on being easy to use – for museums and visitors alike. Museums can use the findings to take greater account of the perspective of visitors when curating and developing their exhibits, thus helping them to remain firmly established as active places in society, both now and in the future.</p><p><strong>About Engagement Migros</strong><br>The Engagement Migros development fund enables pioneering projects in the midst of social change, which break new ground and test solutions aimed at the future. This approach is oriented towards making a difference and combines financial support with coaching services in its Pioneerlab. Engagement Migros is made possible by the companies of the Migros Group thanks to annual funding of approximately CHF 10 million; it has been complementing the Migros Culture Percentage since 2012.</p>

The tool provides visitors with an engaging way to communicate their experiences, while helping museums to consider this feedback when developing exhibits and other attractions.

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