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The Growing Importance of Innovative MEMS Microphones

oice is set to replace buttons in the
future as a means of intuitively
interacting with the environment
V around us. Reaching beyond con-
ventional audio devices such as phones and
recorders, voice control is now being incor-
porated into billions of other devices. Sensors
such as MEMS microphones are key enablers
of the trend toward human-machine com-
munication. According to a report published
by SAR Insight, nearly 6 billion devices are
1
expected to have voice interfaces supporting
features such as voice triggers, voice biomet-
rics, and embedded digital assistants by 2023.
The current Covid-19 crisis has highlighted
two areas where high-performance micro-
phones can play a key role in developing
sophisticated solutions: online meetings with
high-quality audio and health tracking.
Many people are working from home
because of the coronavirus pandemic. As a
result, video conferencing has become the
main way for employees to communicate
with their colleagues. In these situations,
advanced audio features can help reduce
the perceived distance between friends and Figure 1: Video conferences benefit from improved audio quality based on high-
colleagues. Teams all over the world are performance microphones.
using advanced video conference systems
(Figure 1) to communicate more effectively
— something that is particularly important in times when people are by wires. Instead, they are connected over Bluetooth. Like their larger,
not able to meet in person. over-ear cousins, TWS earbuds are equipped with a range of audio
High-quality video and audio are vital for ensuring that online meet- features in which microphones, once again, play a key role.
ings are efficient and convenient. If you think back to your last Skype Active noise cancellation (ANC), for example, was originally devel-
or Zoom video call, what was more important: seeing your colleagues oped to reduce the static noise of engines on flights. Nowadays, more
or hearing them? In terms of poor quality, what would bother you powerful algorithms and better microphones have pushed ANC beyond
more: a blurry image or only hearing a part of each word? Audio often the world of travel, enabling users to eliminate background noise and
is noticed only when it is poor quality. And once we are used to good voices in the office or at home. It is even a feature in today’s TWS
quality, nothing else will do. The main goal here is to ensure that each headsets. Beamforming with microphone arrays enables people to have
speaker’s voice is reproduced as naturally as possible. clear conversations, whether they are working from home or in a noisy
A new class of high-performance microphones is paving the way for environment.
smarter video calls and a host of other features. Smart cameras can pan Headphones, by design, isolate wearers from the outside world.
and zoom in on people and objects to keep up with the action. They While this can provide valuable passive isolation from annoying
can also automatically pivot to keep everyone in view. Smart sound sounds, it is not always convenient. In many situations, we also want to
enhances the voice of the person talking while minimizing background hear what’s going on around us without having to remove our devices
noise. To improve performance levels, high-performance MEMS micro- — for instance, to tune in to announcements in train stations, pick
phones are increasingly combined with advanced audio processing up on surrounding sounds while running in a park, or talk to others.
functions such as blind source separation or beamforming to localize Transparent hearing modes have been developed that enable users to
the position of the user and blur out the background sounds. Today’s create blended augmented audio experiences by telling their high-
video conference systems are fully integrated units that include a performance microphones how much of the outside sound environ-
codec, display, camera microphones, and loudspeakers. ment they wish to capture. Sound is picked up just before it enters the
ears and is altered and played back in real time, creating a transparent,
RISING DEMAND FOR HIGH-QUALITY AUDIO augmented hearing experience. Some manufacturers provide smart
High-quality video conferencing is no longer limited to the business features, such as the automatic activation of transparent hearing when
world. The need to communicate with family and friends — be it in the wearer’s name is called. In the future, it may be possible for micro-
a “virtual happy hour” or digital Easter celebration — has led to the phones to be activated automatically when they detect an approaching
emergence of a number of new tools. New consumer devices such as car or a boarding announcement in an airport, for instance.
Facebook’s Portal, which combines video and audio features, all benefit While transparent hearing is a first step toward emulating human
from high-performance microphones that offer a high-quality audio ears, the experience can be taken one step further with 360° audio
experience. Other new applications are also being developed. Robots recordings. This technology involves equipping earbuds with micro-
that can communicate with people in hospitals or retirement homes, phones that have a low noise floor. The wearer can then use these
for example, already exist today. Better sensors will make these inter- earbuds to record sound experiences such as concerts in 360° audio.
actions increasingly natural. In recent years, true wireless stereo (TWS) This creates an immersive experience that can be played back and
earbuds have emerged as a new device category in the field of hear- relived later or shared with friends. The listener feels like they are
ables. TWS earbuds are not connected to each other or an audio source actually at the concert; without any hiss noise, the recording cannot

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