Additional Tiny Mics on Your Phone: All You Should Know

By Carrie Tsai,  Last Updated: April 24, 2020TIPS

In addition to the 3.5mm headphone jack as well as the main microphone for recording sound, have you ever noticed other tiny holes at the top and bottom of your smartphone? Well, you might indeed have always viewed these tiny holes especially when you charge your phone. However, you probably know nothing about them, right?

It's normal that you don't understand them. After all, these holes on smartphones are very tiny and inconspicuous so that they are easily overlooked. However, they are, in fact, the additional mics on your phone called noise-cancelling mics which play an important role in noise cancellation.

But why do these tiny mics exist in your phone? How do they work? And if they don't work fine, how can you do to fix? Don't be fretful. All the questions are going to be answered. Take your time and read continuously.

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Why Does Your Phone Come Equipped with the Tiny Mics

In fact, the reason is in the name - they are designed to ensure the call quality of your smartphone by employing the noise cancellation technology. Although nowadays audio hardware is well packed into mobile phones to improve call quality, clear calls also benefit from the two overlooked yet essential mic holes on the phones utilizing the noise cancelling technology to cancel out the background noise.

That being said, when making calls on your smartphone, the two noise-cancelling mics assist with cancelling out the background noise around you to ensure high call quality.

Indeed, the existence of the two tiny mic holes on your phone is of great necessity since you certainly don't want your phone calls especially an urgent business call or an important phone interview to be screwed up just due to the background noise around you.

How Do the Noise-cancelling Mics Work

Normally, the vast majority of smartphones utilize the dual-mics noise cancellation technology to remove the background noise. Therefore, on the smartphones, there are usually two noise-cancelling mics. One is at the top while the other at the bottom.

These two mics on your phone work to assist with noise cancellation by sampling the noise nearby and then creating an inverse waveform to cancel out the noise. They work successfully with the reliance on a trick of physics called anti-phase.

If you were to take two identical audio waves, invert one of them and then combine them with each other by matching up the troughs of one wave with the peaks of the other, you are just left with zero wave. This is because the two waves with equal amplitudes but out of phase cancel each other out. This is how noise cancellation works.

When it comes to how the noise-cancelling mics work, in theory, firstly, they capture the incoming ambient noise nearby and send the noise to the noise cancellation circuitry. Then the noise cancellation circuitry produces the inverse noise wave and adds the inverse wave back to the original noise wave. Finally, the two opposite noise waves cancel out each other, causing the removal of the noise.

However, 100 percent noise cancellation is all theoretical. In practice, noise cancellation on phone calls is hard to be perfect. This is led by the imperfection of the electronic conversion. During the noise canceling process, in order to cancel out the original noise wave, the mics need to produce the cancellation noise wave of its own which might not perfectly match up with the original noise wave, leading to the failure of noise cancellation.

Thus, it can be said that 100 percent noise cancellation is almost impossible. In the flipping side, normal noise-cancelling mics can usually achieve -20 and -30 dB of noise reduction.

Why Is It Designed to Be Away from the Main Microphone

If watch carefully, you"ll find that the noise-cancelling mic at the bottom of your smartphone is away from the main mic (also named the voice mic) . Why? Well, this is attributed to the noise-cancelling mics'capability of canceling out the noise picked up by the main microphone.

So if the noise-cancelling mic gets too close to the main mic, the wave and sound intensity of both the voice and the noise collected by the noise-cancelling mic will become very similar, making the noise-cancelling mic cancel out part of the user's voice as it removes the noise. This will eventually make the voice from the speaker very low, leading to poor call quality.

How to Fix When the Mics on Your Phone Aren't Working

Noise-cancelling mics are indeed very useful and efficient tool in assisting with noise cancellation and ensuring high call quality. Nevertheless, it'll be very annoying if they get glitches. After all, if the mics on your phone aren't working, the inability of others to hear you talking back during phone calls especially life-changing ones will make you extremely frustrated.

But don't worry. fixing the noise-cancelling mics not working on your phone is surprisingly simple. Just follow the simple troubleshooting instructions below to fix your mics not working issues quickly and easily.

Solution 1. Restart Your Phone

A quick restart of your phone is the first thing you should do once the tiny mics on your phone get glitches. This is because your phone could sometimes act up due to the non-stop using. Just turn off your phone to refresh the hardware. Then turn it on after waiting for around 30 seconds.

After powering on your phone, all you need to do is check if your mics are working well now. Just check by using the recorder on your phone or making a call to your friend or your family.

Solution 2. Rule out Third-party Apps

Tiny mics not working issue could be led by third-party applications. They could sometimes interfere with your phone. Hence, if a quick restart of your phone cannot fix the mics not working problem, you can try to remove the third-party apps to check if the problem is caused by them.

To disable all third-party apps, you need to run your phone in safe mode. While in safe mode, test if the microphone can work fine by using the recorder on your phone or making a test call. If it is working properly, then the culprit is about your third-party apps.

To enable the microphone on the third-party apps, you can check all the apps one by one by going to the Settings > Apps > App permissions > Microphone permissions. However, it takes so much of your time. The more efficient way is to do a factory reset of your phone. But remember to back up your phone before doing the reset.

Solution 3. Clean up Your Mics

Small openings of mobile phones are vulnerable to dirt or small debris. Hence, the noise-cancelling mics not working issue could be caused by blockages of accumulated dust and debris. You need to clean up the mics on your phone regularly to let them work fine.

Here's How to Clean up:

Method 1. Utilize A Small Pin or A Toothpick

The noise-cancelling mic on your phone is a tiny hole. Therefore, you can use a small pin such as a thin needle or a toothpick to pluck out any dirt inside the mic. To do so, all you need to do first is get a small toothpick and double-sided glue, remove the tip of both ends of the toothpick and then cut the double-sided glue into small pieces to wrap the end of the toothpick.

Then you need to slowly and gently insert the toothpick into the mic hole, twist it around and pull it back out.

Important Warning:

Do not poke the pin or the toothpick too further into the mic. Pushing the toothpick too far may make it break inside the mic.

Method 2. Use A Soft Toothbrush

If poking a pin into your phone is risky, you can also use a soft bristled toothbrush to clean out the noise-cancelling mic. Just insert the super-soft bristled toothbrush into the mic and then gently brush around the mic hole. Then you are able to sweep away any dust or debris.

Solution 4. Run to the Nearest Technician

If you've already tried all the above solutions but still find that your noise-canceling mics don't work properly, you need to run to the nearest technician to seek help. Related technician can professionally help you solve the problem. But it costs a lot of money.

Conclusion

Now you must have a clear picture of the additional tiny mic holes on your mobile phone. They are more than just small holes at the corner of your phone. Instead, they play a crucial role in cancelling out the noise when recording the voice as well as making calls.

However, noise cancelling mics not working problems always seem to happen due to the act-up of your phone, interfere from apps or other devices as well as the vulnerability to dirt blockages. To keep the mics work fine to remove noise, regularly cleaning up them is of great necessity.