Hearing aid design

Thanks for looking into that for me Jeff. I would be very interested to see those notes when you find them. Yeah I'm sure there's no limiter in the 12.00 model either. Lenny

I'll guess that there is some kind of limiter or compressor inside. The manufacturer certainly doesn't want to be sued for blowing out a customers eardrum.

The recommended earphones are ear buds from Etymonic Research. I think these are the ones. They're in the ear rather than over the ear. The idea is to prevent feedback from the mic.

$80... ouch. Note that the EP can deliver a max SPL of 120dB, which is the level capable of trashing your eardrum. You'll need a limiter or compressor.

I can't decode my notes for the source of a directional electret microphone. I'll ask again. I recall he mentioned that a lapel microphone would be sufficient if you used in-the-ear buds for isolation. Also, 55dB gain at 3KHz is overkill. 30dB should be sufficient to get an improvement, without risk of feedback or blowing out your ear drums.

Also, my caffeine deprived brain just had a good idea. Use an iPhone or iPod Touch as a hearing aid. Well, it has already been done:

There are probably other apps.

Just wondering if you have a print out of your hearing test, if you got one. I had a print out on my test, which was ordered by my doctor. I passed mine.

Greg

You could always turn it into an electronic stethoscope. ;-)

I bet that was painful. ;-)

ed

I do, and to a certain extent it looks like an RIAA equalization curve. I do notice though, probably due to the directional nature of high frequency sounds, that if I cup my hand over my ear the intelligibility does definitely improve. So maybe a parabolic reflector for each ear? Remember the horns people used to carry around with them before electronics? At some point I might need a traffic cone, but seriously though, I have a 16 channel stereo graphic equalizer that I'm presently not using. I think I'll set up both channels in tandem and experiment with that in front of the TV with some ear buds. I can simulate about 25DB on each band and I would expect that I would hear a difference with that kind of response. Lenny

ed

Incidentally I did appreciate and looked at the different types of aids sent to me in this thread and it seems like all of them amplify "ambient sounds". None of them seem to have band pass attributes. For me this would be a problem as my low frequency response is fine. Lenny

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someone mentioned using SoundCard in your PC look at Daqarta's website:

I think there are tools to check/verify your hearing using your own system.

I'm interested in your results because I have a similar problem, and had a similar experience with the examiner. This was several years ago, and the price mentioned was about $2000 per ear. When the examiner offered to postpone his vacation several days to process the order I was certain that he would be receiving a large part of this - so much so that I declined to continue.

PlainBill

What we need here is a cheap DIY shotgun Microphone. Mikek

Here's an 8" parabolic Mic that could be used for watching tv.

I like the iPhone idea. Could have frequency response and variable limiting. There are a few amplifier circuits on the web, but I had yet to find one that's smart. Directionality usually requires a stub sticking out. I'm not aware if good amplifiers employ any directionality except for in ear types.

Greg

I got a horn for my birthday !!

Greg

The doctor who advised me the hearing aids from in Atlanta was so fit about getting just the exact product and effective. I require to get someone like that in our new city.

getting just the exact product and effective. I require to get someone like that in our new city.

You should better start with a speaking aid. Your spam is almost un-readable.