Is it possible to make an in-ear microphone with mic found on normal earphones?

Thread Starter

bypassrestrictions

Joined Jun 1, 2021
78
In my other thread here a user said inner ear produces sounds and it can heard through a highly sensitive microphone. I can't find these kind of mics here in India, and even if I found a dealer, I bet those will be medical equipment and might require license or be expensive.

So I thought about this, these days all earphones come with a mic, this is activated by pressing a button on the mic itself, can I disconnect the earphones and use the mic independently? Are there any modifications I can do to make the mic run without pressing the button? Will it be sensitive enough to detect otoacoustic emissions?
 

Alec_t

Joined Sep 17, 2013
12,477
Will it be sensitive enough to detect otoacoustic emissions?
I think any mic capable of that would have to be very small. or have a narrow-bore extension ('ear-trumpet') such that its acoustic input is very close to the eardrum. Positioning it would need professional skills to avoid damage to the eardrum.
The usual medical advice is that "nothing smaller than an elbow should be inserted in the ear" :eek:
 

Thread Starter

bypassrestrictions

Joined Jun 1, 2021
78
I think any mic capable of that would have to be very small. or have a narrow-bore extension ('ear-trumpet') such that its acoustic input is very close to the eardrum. Positioning it would need professional skills to avoid damage to the eardrum.
The usual medical advice is that "nothing smaller than an elbow should be inserted in the ear" :eek:
I was thinking of adding a sponge or foam 2cm away from the mic found in earphones and insert the mic into the ear, the sponge or foam will block the external sounds, the mic would be at just the right distance from the tympanic membrane to detect otoacoustic emissions.
 

Audioguru again

Joined Oct 21, 2019
4,129
You need a lot more than a tiny extremely sensitive microphone. You also need something that produces the sounds that the inner ear vibrates with and something to cancel the original sounds so that you can measure the vibrations produced by the inner ear.

I am 76 years old with "normal-for-my-age" high frequency hearing loss. In the hearing aids store I have had hearing tests done in a noise-proof room (I can hear my heatbeats) with headphones and the audiologist feeds many frequencies one at a time starting with very low levels and I must raise my hand to show that I hear it. Another test is with the Otoacoustic Emissions tester that feeds pink noise (it produces many simultaneous random frequencies) then picks up the emissions caused by the inner ear hairs vibrating. Some kind of special circuit is used to cancel the original pink noise sounds so that the extremely low level vibrations from the middle ear can be measured.

I found this in Google: "Otoacoustic emission test: a type of hearing test that measures an acoustic response produced by the inner ear (cochlea), which in essence bounces back out of the ear in response to a sound stimulus. The test is performed by placing a small probe that contains a microphone and speaker into the patient's ear."
 

DickCappels

Joined Aug 21, 2008
8,169
Did you know that earphones (the things you stick in you ear) can also be used as microphones? The main drawback is that you will be getting a huge amount of the signal from the bone and muscle path and very little to none via the air path, which is how you would get the high frequency parts of speech including fricatives. You would have to use filtering to make the speech clear but you probably can't get the fricatives back.
 

Yaakov

Joined Jan 27, 2019
4,023
I was thinking of adding a sponge or foam 2cm away from the mic found in earphones and insert the mic into the ear, the sponge or foam will block the external sounds, the mic would be at just the right distance from the tympanic membrane to detect otoacoustic emissions.
This is the basic apparatus for detecting otoacoustic emissions. A cheap electret might scavenged from a cheap headset isn't going to cut it. (figure from here)

1637505660341.png
 

Thread Starter

bypassrestrictions

Joined Jun 1, 2021
78
Did you know that earphones (the things you stick in you ear) can also be used as microphones? The main drawback is that you will be getting a huge amount of the signal from the bone and muscle path and very little to none via the air path, which is how you would get the high frequency parts of speech including fricatives. You would have to use filtering to make the speech clear but you probably can't get the fricatives back.
I'm assuming for this I have to remove the shell of the earphones.
 

MisterBill2

Joined Jan 23, 2018
10,580
Did you know that earphones (the things you stick in you ear) can also be used as microphones? The main drawback is that you will be getting a huge amount of the signal from the bone and muscle path and very little to none via the air path, which is how you would get the high frequency parts of speech including fricatives. You would have to use filtering to make the speech clear but you probably can't get the fricatives back.
NOT ALWAYS!!!! Only transducers that are able to generate voltages can serve as microphones. A crystal earphone will make a quite good microphone, and a higher impedance magnetic earphone will also serve as a "fair" microphone, but not nearly as high an output voltage cor a given sound level. The crystal phones make the better mics, but I have not seen one of them offered for sale in 20 years. Those tiny magnetic earphones will need a large amount of amplification. The bigger, outside the ear, phones that are actually miniature speakers will do better, but still much lower output than a good magnetic microphone.. BUT the microphone on most headsets is an electret microphone, and it will not work as an in-ear mich because it requires pressure in the diaphram to produce any output, and it is not sensitive to bone vibration.
 

Audioguru again

Joined Oct 21, 2019
4,129
Why do you want to make this complicated medical device? Can't your doctor measure "otoacoustic emissions" on your baby to tell you if the baby is deaf? Oh, you don't have a doctor?
How will you know if the sounds made by the device are too loud and are harmful?
 

MisterBill2

Joined Jan 23, 2018
10,580
Why do you want to make this complicated medical device? Can't your doctor measure "otoacoustic emissions" on your baby to tell you if the baby is deaf? Oh, you don't have a doctor?
How will you know if the sounds made by the device are too loud and are harmful?
Quite probably the intent is for it to be a communications device, which is an application that I have read about several times over the years. The reason is that it allows the use of communications without being obvious, or even detectable. For some applications that is important.
 

Audioguru again

Joined Oct 21, 2019
4,129
If somebody hears their ears talking to them with nobody there then they have a mental problem.

A baby cannot raise their hand when they hear a test tone.
A person who is lying about being deafened by work needs the otoacoustic emissions test to prove that he is lying and should not get disability payments.
 
Last edited:

MisterBill2

Joined Jan 23, 2018
10,580
I can tell you that those persons on patrols through the tropical jungle never had a chance to wear ear protection devices, and they were subject to many loud explosions and lots of noisy gunfire, and the occasional loud pop of a Claymore mine banging off nearby. Those who did not suffer a bit of hearing damage were those already damaged. You can do the mumble jumble til your ------ fall down and it will change nothing at all. Some folks have missing arms or legs and the damage is easy to spot. Some have gone nuts and their actions give the damage away. And some others just do not hear what you are saying.
So keep that in mind.
And always be sure that brain is fully in gear before putting mouth in overdrive. ( That was posted on a shop wall at one place I worked.)
 

MisterBill2

Joined Jan 23, 2018
10,580
Hello,

Have a look at the microphones on this page:
https://www.directindustry.com/prod/knowles-electronics-llc-127265.html

Bertus
Most of those microphones will not also work as earphones. THAT was the main point of the original earphone/ microphone device. It did not require a separate microphone.. And in the human ear there is no mechanism present for generating sound, only for detecting it. That information came in a private tutorial from an actual MD type doctor who was able to show all of the photos and drawings and diagrams, including the nerve locations. So all of theconstant sounds that I hear are the results of seri0us nerve damage. Nearby explosions will do that, it has been proven.
 

Audioguru again

Joined Oct 21, 2019
4,129
MisterBill2, are you talking about tinnitus, which is a constant "ringing sound" when there is no external sound?
This thread talks about the completely different otoacoustic emissions which are produced by the cochlear hairs in the ear vibrating by nearby sounds, then the hair vibration levels are measured with a very sensitive microphone after the original sound is cancelled. Low vibration levels indicate hearing loss.

I hear faint and very high frequency tinnitus sounds all the time due to my age of 76. Most old people have high frequency hearing loss and tinnitus, like me. The Pfizer Covid-19 vaccine shots I got made the faint tinnitus a little louder like other people rarely reported.
 

MisterBill2

Joined Jan 23, 2018
10,580
I hear that sound very loud, about 80dB, all the time, 24/7/365, for as long as I can remember. About 7khz. And the fine little hairs only get vibrated by external sounds, and so any sound picked up inside the inner ear has arrived from outside, either via the eardrum and the little bones, or by the whole skull vibrating from louder sounds. Nothing inside the ear makes sounds! That is the mind playing back memories. It happens all of the time, the important part is to know that it is the brain doing a random playback.
No way is a microphone going to pick up any sound because it does not exist as a physical vibration at all. It is all a nerve signal, usually caused by some sort of damage, such as a hard hit on the head or a nearby explosion or even some act of some disease. Had all three kinds multiple times. Soif that is what the TS is wanting to hear then a probe connected to nerves is the solution. Good luck on that part!!
 

DickCappels

Joined Aug 21, 2008
8,169
I apologize in advance for this digression. Feel free to skip ahead, you won't miss anything important.

Back in about 2002 I experienced tinnitus that was painfully loud, so I went to a big hospital in the big city and was give a hearing test. When the test came back the doctor took my hands in his, looked into my eyes and said "You are getting old."

Since then rest, relaxation, and antihistamines have helped a lot (I used Xanax for a few weeks but I could only get a three supply at a time, and grew tired of the hassle.)
 

Thread Starter

bypassrestrictions

Joined Jun 1, 2021
78
Most of those microphones will not also work as earphones. THAT was the main point of the original earphone/ microphone device. It did not require a separate microphone.. And in the human ear there is no mechanism present for generating sound, only for detecting it. That information came in a private tutorial from an actual MD type doctor who was able to show all of the photos and drawings and diagrams, including the nerve locations. So all of theconstant sounds that I hear are the results of seri0us nerve damage. Nearby explosions will do that, it has been proven.
My original intention was to use the mic found in earphones, not the earphones themselves.

MisterBill2, are you talking about tinnitus, which is a constant "ringing sound" when there is no external sound?
This thread talks about the completely different otoacoustic emissions which are produced by the cochlear hairs in the ear vibrating by nearby sounds, then the hair vibration levels are measured with a very sensitive microphone after the original sound is cancelled. Low vibration levels indicate hearing loss.

I hear faint and very high frequency tinnitus sounds all the time due to my age of 76. Most old people have high frequency hearing loss and tinnitus, like me. The Pfizer Covid-19 vaccine shots I got made the faint tinnitus a little louder like other people rarely reported.
I was looking at Bose Sleepbuds and they mentioned that sounds combine in the inner ear, this is what lead me to this question, when nsaspook mentioned some article about human ear frequency selectivity, searching for it on the net, got me to otoacoustic measurements.

I also have tinnitus and I want to mask it, this is the reason for asking how to make a microphone as I thought it might give me insight into how sounds combine in the inner ear, which might allow me to make a masking sound.
 
Top