In general, we generally refer to the microphone of our mobile in the singular without this being really true: mobiles equip more than one microphone, usually two (and further). The aim is to improve the detection of assistants, reduce noise in calls and offer different audio tracks in video recordings.
Despite the “small” size of a mobile phone, so much technology is stored inside the device that smartphones have become a multidisciplinary tool. They call, they allow to listen to music, to watch television, they make game console, they record video and even audio. Paradoxically, sound recording has evolved quite discreetly.
In general, the more microphones, the better the audio quality.
Bottom microphone on the Samsung Galaxy Note 20 Ultra
More is usually an indication that that particular aspect is better. Still in general, this direct proportionality has no effect on the number of cameras or the number of megapixels, for example. Even so, the best mobiles are those with the most microphones. And that’s for one main reason: with it they offer more audio features.
As far as we speak in the singular, phones include more than one microphone. The usual thing is that they have a few to capture audio from two different sources; to reach stereo sound for calls and also for voice recorder.
The number of microphones also affects the quality of the recorded sound because, by merging the different audio channels provided by the microphones on a single track, the resulting sound becomes more nuanced, picks up low frequencies and the mobile can reduce the noise obtained so that the track provides greater cleanliness. Still on paper, we have already said that more does not mean better.
With professional video recording and audio zoom already included in many high-end mobiles, manufacturers they usually incorporate a fourth microphone on the back of the phone, in the goal area. This way the audio is captured at 360º; make videos with sound closer to the scene that was recorded. It is even possible to amplify the audio log when enlarged. This allows for greater realism.
Where are the microphones placed on the phone?
Microphone next to the SIM tray (Xiaomi 11T). Who didn’t get the wrong hole?
It is impossible to answer this question categorically since each manufacturer place the mics as you see fit and how you placed the internal components. As each microphone needs an exit to the outside and the microphone must be connected to the plates by means of a cable (normally flexible or flat), the interior design plays a decisive role in the placement of the microphones.
The interior design of the mobile plays a decisive factor in the placement of the microphones: they must have an output to the outside
Look at your mobile. The usual thing is to have a mic (or two) at the bottom of the device: sometimes with a hole and others taking advantage of the output of external speakers; on the top edge there is usually another hole for the third mic, the noise canceling one (it is also usually placed in the pager); and in the rear area of the lenses there can be another hole for the fourth microphone, the one dedicated to video recording.
Zoom audio in the Google Pixel 6 pro taking advantage of its rear mic
Each brand and model of mobile can place the microphones in a different place, although the order we have defined is more than usual. The number varies depending on the benefits: noise cancellation is usually included for calls; which triggers the inclusion of three microphones. If the mobile is a range with some specialization in video the fourth mic is usually seen between the rear cameras. There may even be more.
The voice assistant benefits from the increased number of microphones, so you can listen to commands from anywhere
Along with improvements in recording quality, audio zoom, and noise suppression, increased mic count benefits smart assistant. Have you noticed that a soft “Ok, Google” is usually enough for the mobile to wake up and listen to you? The sensitivity and number of microphones help detect voice from any angle around the mobile.
Disconnecting one microphone disconnects all
Rear microphone on the Google Pixel 6
Although they may have many microphones, operating systems treat this hardware in unique ways. It is, apps won’t be able to use them if the user denies them permission to access the microphone. Therefore, just blocking said permission will cause none of them to work.
From Android 11, the system warns with a green dot when the microphone is active; with global management of audio capture in Android 12. Keep track of mic usage and the software that used them, it is a good way to protect privacy.
