Test Top Microphone Of Cell Phone

Thread Starter

MrAl

Joined Jun 17, 2014
8,497
Hi,

Anyone know how to do this without taking the phone apart?
The phone is very difficult to get apart because it has a non replaceable battery inside. It takes a heat gun and guitar picks to get the back off and i dont want to mess with that.

The problem is i think there is something wrong with the top microphone. The bottom one works ok.

If i were to have to replace it then:
I checked on the web and all they show is the replacement of the lower microphone so that does not halp.
But i hate to have to do that anyway.

Although ti may still work, i am doubting because there was a sim removal tool inserted into the top hole which is the 2nd microphone not the sim release hole.

Also, anyone know what the 2nd mic at the top of a cell phone is supposed to be for?
I cant find anything about this for any phone.
 

Yaakov

Joined Jan 27, 2019
3,565
General information: the 2nd and or 3rd microphones are for ambient pickup, This is used for things like video recording and speech recognition.

A possible test is to use a voice memo app for the primary (lower) mic, and the video recording for the secondary and tertiary mics. If any are muffled or low amplitude you might have a problem with the respective microphone.

Rubbing a finger over the mic can help determine if you are recording from the one you expect.
 

Thread Starter

MrAl

Joined Jun 17, 2014
8,497
General information: the 2nd and or 3rd microphones are for ambient pickup, This is used for things like video recording and speech recognition.

A possible test is to use a voice memo app for the primary (lower) mic, and the video recording for the secondary and tertiary mics. If any are muffled or low amplitude you might have a problem with the respective microphone.

Rubbing a finger over the mic can help determine if you are recording from the one you expect.
Samsung Galaxy.

What i was wondering is, is it possible that both mics are used for voice when 'talking' out a mesage?
That's where you speak and it gets turned into text in the Messages app.
I also wonder if it would hurt to leave it non working.
I checked on the web and i see a lot if vids about changing the bottom mic and charging USB connector but not a single one about the top mic. I also cant find a GOOD picture of the mic itself. It looks like a shiny metal square but i cant see any holes in it. I was trying to figure out if poking it would actual puncture the diaphragm or not.

I do see this happened to other people too on other devices.
 

Yaakov

Joined Jan 27, 2019
3,565
Samsung Galaxy.

What i was wondering is, is it possible that both mics are used for voice when 'talking' out a mesage?
That's where you speak and it gets turned into text in the Messages app.
I also wonder if it would hurt to leave it non working.
I checked on the web and i see a lot if vids about changing the bottom mic and charging USB connector but not a single one about the top mic. I also cant find a GOOD picture of the mic itself. It looks like a shiny metal square but i cant see any holes in it. I was trying to figure out if poking it would actual puncture the diaphragm or not.

I do see this happened to other people too on other devices.
The second microphones are used for ambient sound (for noise cancelation when doing speech recognition, that is, voice to text) and for the video recording. If you try the tests I mentioned, you might find it is still working or it might be inconclusive.
 

Thread Starter

MrAl

Joined Jun 17, 2014
8,497
The second microphones are used for ambient sound (for noise cancelation when doing speech recognition, that is, voice to text) and for the video recording. If you try the tests I mentioned, you might find it is still working or it might be inconclusive.
Yes i tried that, but the problem is, i dont know what the default behavior was before.
In other words, for a given application if it does not work i dont know if it worked in that application before the 'injury'.
However, i think i tested the speech to text and i thought i talked into the top microphone but that was some time ago so i cant remember exactly.

But what i was wondering was if the software might take the loudest sound as the main mic and the lower sound as the secondary mic. So if you talk into the bottom mic, it uses that, and if you talk into the top mic, it uses that instead. Problem is, so far nothing responds to the top mic, but as i said, i dont know if any app i have used that before or not so the test is inconclusive.
Amazingly, there is even a special code you can type that puts the phone into 'test' mode where you can test the sensors. Trouble there is that it only has one test for the 'microphone' (note the singular microphone not 'microphones' plural). The test makes a weird noise like a spaceship if the 'microphone' (again singular) works. If "it" (singular) does not work it does not make a sound. It makes the right sound, but unfortunately i dont know if it is testing both mics or just the lower one. I cant find much on this either on the web.

What really astonishes me is why cant i find anything about the 'second' (top) mic anywhere on the web. I found vids to replace the bottom mic in several places, but not a word on the top one.
I also can not find a clear picture of either mic. All i see is a rectangular metal box, very small less than a pinky finger nail. The problem with all the pics is that they are all a top view looking down at the PC board, with NONE showing what we could call the "front" of the mic where the sound would go in. If i could get a pic i could examine the 'front' and see if it looks like it could be damaged. I did manage to find one 'reply" on another site that said that the top mic on a tablet device (not a phone) would not get damaged because the mic was oriented on an angle inside so anything poking in would not rupture the diaphragm or anything like that.

My gut feeling though is that it did get damaged.
My other feeling is that if the top mic doesnt do much or is not used much i dont have to bother trying t fix it.

But i forgot to say 'thanks' for the previous info and any other ideas or suggestions no matter how far out there i'd be very appreciative to hear, thank you.
 
Last edited:

Thread Starter

MrAl

Joined Jun 17, 2014
8,497
General information: the 2nd and or 3rd microphones are for ambient pickup, This is used for things like video recording and speech recognition.

A possible test is to use a voice memo app for the primary (lower) mic, and the video recording for the secondary and tertiary mics. If any are muffled or low amplitude you might have a problem with the respective microphone.

Rubbing a finger over the mic can help determine if you are recording from the one you expect.
Actually what i did not consider at first was that if the top mic IS WORKING then your test is very good if an app can use the second mic. One of the problems was that i wasnt sure which app would use the second mic but again what i did not consider at first was that if i tried several apps i MIGHT find one that it works in.
I finally found a site that suggested using the video recorder to test the second mic. The mics are very sensitive so it's hard to tell, but i placed a finger over the bottom mic while vid recording and speaking directly into the top mic and it sounded pretty much like when doing the same with finger over the top mic and speaking into the bottom mic, so i "think" the second mic is working, thank God :)

It was very unsettling to think how stupid we can be sometimes. One of the problems is that the hole for teh mic looks just like the hole for the sim drawer ejection, and it was at the top and i have seen several phones with the hole at the top so i didnt think too much about if it was right or wrong. Because of that i let my guard down and did not think about the consequences if it WAS NOT THE RIGHT HOLE. That something that i almost always (99.9999 percent of the time) consider when dealing with electronics because one false assumption can lead to irreversible damage. I had a really nice calculator very long time back with nice fluorescent digit display and went probing with an oscilloscope to see what some of the waveforms looked like, with a scope that i knew needed work because of a high voltage insulation issue. Well, a spark jumped from the tip of the scope probe to some part of the PC board inside and bam, the calculator was gone forever. I was heartbroken, and could not find a replacement anywhere as it was sort of outdated at the time as red LEDs were becoming more common in calculators.

I am hoping the test i did was sufficient but i guess time will tell. It looks like it could be working and i finally found a site that suggested that phone manufacturers knew this was an issue so they positioned the mic off to the side of the hole, so i think it may be working. However, there is still the remaining issue about if the water proofing design was compromised. I will have to start carrying my phone around in a plastic baggie :)
Amazingly, i saved my nice lunch sandwich in a sealed plastic baggie when on a white water canoe trip when our canoe tipped over and everything got soaking wet, except the big sandwich.

Still any other ideas would be appreciated, thanks again.
 
Last edited:
Top