True Wireless Stereo (TWS)  devices will be ready for any acoustic environment in everyday life  


Redefining hearing and communication with TWS earbuds and hearables

Han Dirkx is passionate about mental well-being and the desire to create a stress-free society for everyone. He firmly believes inner peace creates outer peace: when you feel well mentally, not only do you benefit, but so do the people &ndash; and the world &ndash; around you. That&rsquo;s why he started AlphaBeats, a health tech startup that uses neurofeedback technology and the user&rsquo;s music to reduce stress. Through AlphaBeats, he has embarked upon a new journey to transport people to &ldquo;alpha mode.&rdquo;Han sat down with us recently to answer a few questions about AlphaBeats, his role as CEO, thoughts on diversity in startups and the differences between American and Dutch companies.&nbsp;<h2>Did you ever picture yourself as a CEO?</h2>No, I didn&#39;t really see myself as CEO. I also didn&#39;t really have the ambition to become a CEO, but that&rsquo;s what it&rsquo;s like with small companies. Each person does what they need to do to help the company grow. What I like is to do new things, and being a CEO was completely new for me, especially being a CEO of a health tech company. But it&rsquo;s an adventure, so why not? I am not afraid of doing new things and that means sometimes you fall really hard. But on the other hand, if you are afraid of making mistakes, you will never experience the great things we [entrepreneurs] experience. That&#39;s the great up-side of just going for something. Being a CEO was completely new for me, especially being a CEO of a health tech company. But it&rsquo;s an adventure, so why not? I&#39;m not afraid of doing new things, and that means sometimes you fall really hard. But on the other hand, if you are afraid of making mistakes, you will never experience the great things we [entrepreneurs] experience. That&#39;s the great up-side of just going for something. At a certain moment, we had to decide who would be the CEO. The whole team said, &ldquo;Okay, we think Han is the most appropriate person for that, for the moment.&rdquo; And that&#39;s also how I looked at it: I was the most appropriate person at that moment, and the nice thing is, I like it and still grow every day. Just like life, startups are kind of organic.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1651654330146-handirkx2.webp" style="width: 766px;" class="fr-fic fr-dib"><h2 id="isPasted">What is your view on diversity, particularly in the startup world?</h2>There is a lot of diversity in society, in the world around us, but what you see is that a lot of things are moving in the wrong direction because people don&#39;t understand each other anymore ... and not only men and women, but diversity on different levels. I think if you want to bring great innovative solutions to the market, you need a good &ldquo;sample&rdquo; of society. Half of the people on this earth are women and half are men, so it&#39;s really ridiculous that we don&#39;t see that same ratio in companies.So, yes, I believe in diversity in teams. I believe you should hire the best person for the job, but I also believe that to make progress, we need initiatives from governments and from organizations like Fe+male Tech Heroes and InspiringFifty that will push women to the front. We need women, and we need people from diverse backgrounds and ethnicities, not just fat, old white men in our companies.Diversity between ages is also very important, because you mustn&rsquo;t only have young people or older people in teams. It&rsquo;s better to have a nice balance, and I think we have that balance of society in our team. Personally, I don&#39;t like male-dominated things, dominating cultures. I prefer a more female-dominant culture. But that&#39;s a personal note. I&#39;m a bit more focused on the soft side than on the hard side.<h2>You put out a call to attract females to test the AlphaBeats app. Data collection is often biased toward men, so why is it important for AlphaBeats to include data from female beta testers?</h2>For the moment, we are not making the differentiation between male or female. I admit you want data which reflects the difference between male and female, but we haven&rsquo;t analyzed that yet. What we do know is if you look at the mental self-care industry, a broader view of the available services and apps such as Calm or Headspace, but also yoga classes, meditation classes, then we see females are overrepresented in our data. I think men are a little bit behind in this sphere, because for women, it&#39;s already quite normal to say, &ldquo;Okay, I&#39;m feeling a little bit stressed right now, so I&#39;m going for a yoga session this afternoon.&rdquo; So, I think we men are still lagging behind women and we need to include these routines to improve our mental well-being. But if you look at the AlphaBeats app, it&#39;s kind of gender-neutral at the moment. We have been focusing on general UX. Of course, in time we will need to decide if we need to make any differentiation in the UX for men or women. Right now, we are focusing on the artificial intelligence, which makes it possible to show personal preferences and to make personalized music recommendations.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1651654391530-handirkx3.webp" style="width: 766px;" class="fr-fic fr-dib"><h2>You just returned from CES in Las Vegas. What is your take on the American startup ecosystem?</h2>I think diversity is kind of a buzz word at the moment. &ldquo;Impact&rdquo; and &ldquo;diversity,&rdquo; you hear those a lot. I think in America, it&rsquo;s more common that you have women in top positions. So, they have more opportunity there today. In the Netherlands, it&rsquo;s still expected that a woman will become a mother and will take care of the family first because that&rsquo;s a priority. In America, it appears to me that it&#39;s more normal that women can say, &ldquo;Now I&#39;m a mother, but also I&#39;m a CEO.&rdquo; So, that means I&#39;m also working 24 hours a day, in addition to managing the family&rsquo;s affairs. But maybe her husband is taking care of that, or she gets help from a nanny. So, it&rsquo;s more common for females to be in top positions because they feel they have the same privileges as men. You still can have kids, but that doesn&#39;t mean women have to stay home and take care of the kids. And that&#39;s still something you see in the Netherlands. But luckily there is a good possibility in the future that our daughters will become top business leaders. That&#39;s what my father-in-law, who is over 80 &ndash; and a really smart guy &ndash; says when you ask him what he&#39;s proud of. He says: &ldquo;I&#39;m really proud that I made three daughters and they are really self-sufficient, depending only on themselves, so they can stand on their own.&rdquo; I think that&#39;s good, you know. The next step is that we accept a society where women can have top positions along with being a mom and dads who also take responsibility for the home. This should be the norm. It should happen sooner rather than later. But on the other hand, being a dad or mom is not less than being a CEO. Being yourself and doing what you like to do the most makes true heroes.&nbsp;

Han Dirkx is passionate about mental well-being and the desire to create a stress-free society for everyone. He firmly believes inner peace creates outer peace: when you feel well mentally, not only do you benefit, but so do the people – and the world – around you.

Fe+male Tech Heroes role models 26 Han Dirkx: "I'm not afraid of doing new things. That's how I've become an entrepreneur"

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.So what are the inherent advantages of USound MEMS loudspeakers compared to conventional electrodynamic and balanced armature&nbsp;speakers? <h3>SMALLER&nbsp;SIZE</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>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.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.This reduced thickness frees up more real estate for other components, such&nbsp;as<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> <h3>PCB-BASED</h3>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; <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>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. <h3>SMALLER MOVING MASS, THEREFORE LOWER&nbsp;VIBRATIONS</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>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. <h3>NO ELECTROMAGNETIC&nbsp;RADIATION</h3>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). <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>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.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. <h3>SUMMARY</h3>USound MEMS loudspeakers offer many benefits over conventional&nbsp;loudspeakers.<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>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.

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

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?Is there an objective way to answer this? Or does it all depend on personal&nbsp;preference?The truth, as so often, is somewhere in the&nbsp;middle.The first question we need to answer is: “what should a speaker sound&nbsp;like?”&nbsp;The short answer is (after decades of&nbsp;research):<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>The debate about this is&nbsp;basically 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).<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>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;target for speakers is Flat on-axis, controlled sound power output (smooth&nbsp;directivity).Now, the same question can be asked for headphones: “what should a headphone sound like?” (in terms of: What is the ideal frequency response of a headphone”), and the short answer is: “it’s not that&nbsp;simple”.The answer is simple for speakers (not that simple really, but it has been answered), but for headphones, it is much more&nbsp;difficult.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:<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>The important thing is: We “hear” this boost even when listening to speakers – because our ears are&nbsp;always 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;target frequency&nbsp;response?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.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.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!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.<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>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.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.<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>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.

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Redefining hearing and communication with TWS earbuds and hearables

Fe+male Tech Heroes role models 26 Han Dirkx: "I'm not afraid of doing new things. That's how I've become an entrepreneur"

Inherent characteristics of USound MEMS speakers

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