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Analog to Digital Converters

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CCvickers!! I did wear one!! :slight_smile: The wind was still loud wow!

MichaelJ Sounds good to me!!

Zafdor!! I know I am missunderstanding something!! on a 16 bit A/D. There has to be a max spl from the micro phone that it can handle? What is it??

@HonkyTonkJohn said:

CCvickers!! I did wear one!! :slight_smile: The wind was still loud wow!

MichaelJ Sounds good to me!!

Zafdor!! I know I am missunderstanding something!! on a 16 bit A/D. There has to be a max spl from the micro phone that it can handle? What is it??

Most modern hearing aids can pass an input of approximately 110 dBSPL without distortion.

In reply to @HonkyTonkJohn

@HonkyTonkJohn said:

Research, is that a 16 bit hearing aid? if so does the 24 bit handle more?

Also what hearing do you think can handle a input 110? Brand model??

It’s unlikely that the 24 bit processor will increase your allowable peak input. My generalized 110 dBSPL input level should hold true for most quality hearing aids. The weak point in most systems will be the receiver, which may start to distort at high output levels.

@Research said:

It’s unlikely that the 24 bit processor will increase your allowable peak input. My generalized 110 dBSPL input level should hold true for most quality hearing aids. The weak point in most systems will be the receiver, which may start to distort at high output levels.

I will have to disagree, now! i believe the input is not capable of 110dbspl!!it would be lucky to hit 100 dbspl!! The hearing aid focus is not on sounds above 90 dbspl and if it is its not much over that!! I do belive they need too, I think they are but the microphone isn’t up to it yet!

I don’t think extremely high dynamic range hearing aids are necessary for most losses. This is because most all hearing loss is accompanied by some degree of recruitment. (Thought to be mostly caused by degenerated outer hair cells.)

People with severe/profound loss may have only 10 to 20db of usable dynamic range.

That being said, it is important that the aid not develop audible distortion products from very loud inputs. I believe most aid designers include some form of limiting immediately following the mikes. Ed

People with severe/profound loss may have only 10 to 20db of usable dynamic range.

YES!

On top of a low dynamic range ear, the dynamic range of a hearing aid microphone is only about 83dB … and yet I keep seeing posts about hi-fi hearing aids with CD resolution.

A damaged human ear is just that - a damaged human ear. It is NOT a damaged human ear which digital technology can magically restore to 100% health!

I think that many people feel that technology - or lots of money in the bank - can solve ANYTHING … when it can’t.

@EnglishDispenser said:

YES!

On top of a low dynamic range ear, the dynamic range of a hearing aid microphone is only about 83dB … and yet I keep seeing posts about hi-fi hearing aids with CD resolution.

A damaged human ear is just that - a damaged human ear. It is NOT a damaged human ear which digital technology can magically restore to 100% health!

I think that many people feel that technology - or lots of money in the bank - can solve ANYTHING … when it can’t.

English, you speak strong!! All I am saying is if the stupid hearing aid is amplifing distorted sounds it does no good for me at all!! I would rather not hear. Like you! your not hearing my concern! All you talk about is dynamic range( Dynamic range is important!!) I want a hearing aid that will not clip on the input on a loud stage!you have a hearing aid that will do that english?? Answer that will you? Also do you wear a hearing aid? I am not in neverland! the day that I stop looking for a better product is the day I am dead!! English you are a saleman! you take the product available and sell it! Check the specs, there are limits to its capablities before the end of a damaged ear depending on the damage and what kind of damage! Its like they brain wash you audioloist to think one way, all on the out put, add alittle compresstion here and limit it here! your all the same. You don’t know the true specs on your products. A microphone I don’t care what kind it is, has limits on how much sound it can handle on the input, they all do! You go over that limit and its distorted. So you take that distorted siganl and feed into an ampilifier and amplify I don’t care if you give it 10 db over 80 db it sucks because it is already distorted. Then you add the distortion that the reciever adds to it because it is an electronic piece of equipment and you get more noise! Is there a pruduct that will handle an input of 110 db spl?

Thanks
John

HonkyTonkJohn and Senior Members,

I am a new member and this is my first post. HTJ, I understand exactly what you are asking. If the input is distorted by the microphone’s dynamic range limits or by clipping of the ADC, then there can be no way to eliminate this downstream. Now with respect to 16 bit vs 24 bit ADC (and with apologies for oversimplification in my description), this allows increased number of different volume levels that can be resolved and reproduced (and is not related to maximum sound pressure level). Subjectively, this has the effect of differentiating between more upper level harmonic overtones and subtle detail. Increasing sampling frequency increases bandwidth and reduces aliasing-induced phase distortion. Subjectively, this reduces smearing of fine detail in the audible range of those people who can still hear something between 8 KHz and say 10 KHz, even if they do have severely compromised hearing in the 3-4 KHz range. Together, these improvements increase the textural detail of complex orchestral ensembles and increase the the tonal accuracy and and quantitative relationship between overtones and fundamentals. All of this improves the perception of musical realism and one’s emotional enjoyment. So for me, the question boils down to: “who knows of a hearing aid that nows uses the Woverine 24-bit chip from Sound Design Technologies?” Even though I have compromised hearing (see attachment), I can still hear quite well the difference between 16 and 24 bit processing and 22, 88, 176, and 198 kHz bandwith.

I see from the dates of the posts on the previous page, I am a little tardy in my reply and that I mispelled Wolverine. Ooops. Not a good first attempt.

Edited

What do you want to know?

The mics are analogue MOSFET, A-D is done at the input stage of the amp circuit.

Modern aids use a pre-amp comparator to observe degradation/feedback in the circuit. If the A-D or the processing destroys the signal too much or you start getting temporal artefacts, the will revert the signal to an unprocessed/less processed version.

Quantisation issues aren’t really a problem unless you’re looking for Hi-Fi reproduction and you have near perfect hearing - which you won’t if you are wearing hearing aids.

Speech clarity first, Violin Concertos further down the list. Get a Widex to hear both.

In reply to @HifiDr

@HifiDr said:

HonkyTonkJohn and Senior Members,

I am a new member and this is my first post. HTJ, I understand exactly what you are asking. If the input is distorted by the microphone’s dynamic range limits or by clipping of the ADC, then there can be no way to eliminate this downstream. Now with respect to 16 bit vs 24 bit ADC (and with apologies for oversimplification in my description), this allows increased number of different volume levels that can be resolved and reproduced (and is not related to maximum sound pressure level). Subjectively, this has the effect of differentiating between more upper level harmonic overtones and subtle detail. Increasing sampling frequency increases bandwidth and reduces aliasing-induced phase distortion. Subjectively, this reduces smearing of fine detail in the audible range of those people who can still hear something between 8 KHz and say 10 KHz, even if they do have severely compromised hearing in the 3-4 KHz range. Together, these improvements increase the textural detail of complex orchestral ensembles and increase the the tonal accuracy and and quantitative relationship between overtones and fundamentals. All of this improves the perception of musical realism and one’s emotional enjoyment. So for me, the question boils down to: “who knows of a hearing aid that nows uses the Woverine 24-bit chip from Sound Design Technologies?” Even though I have compromised hearing (see attachment), I can still hear quite well the difference between 16 and 24 bit processing and 22, 88, 176, and 198 kHz bandwith.

Yes there is if you are comparing the I/P and O/P closely enough.

Moreso, you have to do this instanly on 1.2 VDC. No time for twenty times over sampled 198Khz. Wasted processor cycles.

Edited

HonkyTonkJohn, there is a setup that I have used for musicians with good success. Ask for a Unitron brand behind the ear hearing aid with musician microphones. The only option for getting these hearing aid microphones is on their behind the ear hearing aids.

I’m not an engineer that can answer AtoD conversions or that level of technical queries, however I know sound. You want a microphone that will not distort during a show. This is the only type of instrument that I know of that can do it. This has been backed up and developed with Unitron by a man named Marshall Chasin. If you google his name, you will understand what he does.

Good luck,

In reply to @HonkyTonkJohn

@HonkyTonkJohn said:

how do you keep from distorting the microphone?

The mic has a given operating range. Believe it or not mics can withstand explosive decompression.

Below 25dB is irrelevant as the mic noise floor is about this, inputs over 110dB are also irrelevant to speech as the aid isn’t going to do anything with them. That gives you 85dB dynamic range, chop it up as you want.

There will be a calibrated level of sensitivity and a phase angle, why would you be introducing distortion under normal operating conditions. It’s not designed to add anything to the signal.

In reply to @HonkyTonkJohn

@HonkyTonkJohn said:

By the way! Jesus First, Violin second, and speech last! Are you saying a widex will solve my band problems with spl levels up to 115db? Most of the time around 100 to 105 db

Try one on a music program.

Your high input levels are doing over the processing and kicking in the OLC (output limiting compression) or you’re overdriving the receiver and getting harmonic distortion which is usually about 10% at the fully driven state.

1 why do you need the sound to be this loud? (it’s damamging to your hearing and the aid)

2 get a quieter hearing aid music program with the processing turned off and the set to the max.

3 don’t wear the aids in this environment - ER plugs would be better.

All of which is nothing to do with the mic.

AND I also have a Guitarist who is happy with the Unitron music program.

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