Hearing aid design

On Feb 23, 8:23 pm, "Michael A. Terrell" <mike.terr...@earthlink.net>
wrote:
Jeff Liebermann wrote:

My guess is that I'll consume about 20 per year, mostly in small
flashlights, remotes, keyfobs, etc.  I gave away a mess of them to
various friends.  I think I have about 80 of each in the fridge.

http://www.davehylands.com/Machinist/Caliper-Batteries/
He notes that the self discharge rate is not signifigant.  Maybe not.

http://www.lr44buttonbattery.com/lr44-button-battery-vs-sr44-battery/
The LR44 has a shelf life of about 10 years.  Silver-oxide has a 5
year shelf life:
http://www.sr44.com

   Even with those numbers, I'm better off buying a half dozen at a
time.  Unless my health improves to were I can spend more than an hour
or two a week in my shop.

--
You can't have a sense of humor, if you have no sense.
Click to expand...
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny
 
On Sat, 25 Feb 2012 06:59:26 -0800 (PST), klem kedidelhopper
<captainvideo462009@gmail.com> wrote:

I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny
Click to expand...
I had dinner with an acoustic engineer and asked about your hearing
aid problem. He said it was possible and offered some hardware
suggestions, which I scribbled down somewhere. However, he mentioned
an important point which you should consider if you build your own
device. Since you can't hear much at about 3KHz, if you drive the
earphone with too much power, you risk creating additional hearing
damage. You can't tell if the hearing aid is too loud (too high an
SPL). Whatever you build, make sure that it has some kind of limiter
or compressor circuit to keep you from accidentally blowing out your
ear drums from a door slam or sudden loud noise. He also agreed that
500-2800 Hz is about all you'll need for speech.
<http://en.wikipedia.org/wiki/Sound_pressure>
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
On Feb 25, 12:37 pm, Jeff Liebermann <je...@cruzio.com> wrote:
On Sat, 25 Feb 2012 06:59:26 -0800 (PST), klem kedidelhopper

captainvideo462...@gmail.com> wrote:
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny

I had dinner with an acoustic engineer and asked about your hearing
aid problem.  He said it was possible and offered some hardware
suggestions, which I scribbled down somewhere.  However, he mentioned
an important point which you should consider if you build your own
device.  Since you can't hear much at about 3KHz, if you drive the
earphone with too much power, you risk creating additional hearing
damage.  You can't tell if the hearing aid is too loud (too high an
SPL).  Whatever you build, make sure that it has some kind of limiter
or compressor circuit to keep you from accidentally blowing out your
ear drums from a door slam or sudden loud noise.  He also agreed that
500-2800 Hz is about all you'll need for speech.
http://en.wikipedia.org/wiki/Sound_pressure
--
Jeff Liebermann     je...@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558
Click to expand...
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
 
On Sat, 25 Feb 2012 11:24:09 -0800 (PST), klem kedidelhopper
<captainvideo462009@gmail.com> wrote:

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
Click to expand...
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.
<http://www.etymotic.com/ephp/mc5.html>
$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:
<http://reviews.cnet.com/8301-19512_7-10281062-233.html>
<http://itunes.apple.com/app/soundamp-r/id318126109>
<http://itunes.apple.com/us/app/tinnitus-help/id382593362>
<http://www.ind-technik.eu/software/tinnitushelp/>
<http://www.ind-technik.eu/software/hearinghelpforiphone/>
There are probably other apps.



--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
 
klem kedidelhopper wrote:
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny
Click to expand...

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


--
You can't have a sense of humor, if you have no sense.
 
gregz wrote:
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.
Click to expand...

I bet that was painful. ;-)


--
You can't have a sense of humor, if you have no sense.
 
klem kedidelhopper <captainvideo462009@gmail.com> wrote:
On Feb 25, 12:37 pm, Jeff Liebermann <je...@cruzio.com> wrote:
On Sat, 25 Feb 2012 06:59:26 -0800 (PST), klem kedidelhopper

captainvideo462...@gmail.com> wrote:
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny

I had dinner with an acoustic engineer and asked about your hearing
aid problem. He said it was possible and offered some hardware
suggestions, which I scribbled down somewhere. However, he mentioned
an important point which you should consider if you build your own
device. Since you can't hear much at about 3KHz, if you drive the
earphone with too much power, you risk creating additional hearing
damage. You can't tell if the hearing aid is too loud (too high an
SPL). Whatever you build, make sure that it has some kind of limiter
or compressor circuit to keep you from accidentally blowing out your
ear drums from a door slam or sudden loud noise. He also agreed that
500-2800 Hz is about all you'll need for speech.
http://en.wikipedia.org/wiki/Sound_pressure
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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
Click to expand...
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
 
On Feb 25, 4:24 pm, gregz <ze...@comcast.net> wrote:
klem kedidelhopper <captainvideo462...@gmail.com> wrote:
On Feb 25, 12:37 pm, Jeff Liebermann <je...@cruzio.com> wrote:
On Sat, 25 Feb 2012 06:59:26 -0800 (PST), klem kedidelhopper

captainvideo462...@gmail.com> wrote:
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny

I had dinner with an acoustic engineer and asked about your hearing
aid problem.  He said it was possible and offered some hardware
suggestions, which I scribbled down somewhere.  However, he mentioned
an important point which you should consider if you build your own
device.  Since you can't hear much at about 3KHz, if you drive the
earphone with too much power, you risk creating additional hearing
damage.  You can't tell if the hearing aid is too loud (too high an
SPL).  Whatever you build, make sure that it has some kind of limiter
or compressor circuit to keep you from accidentally blowing out your
ear drums from a door slam or sudden loud noise.  He also agreed that
500-2800 Hz is about all you'll need for speech.
http://en.wikipedia.org/wiki/Sound_pressure
--
Jeff Liebermann     je...@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

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

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
Click to expand...
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
 
On Feb 25, 4:24 pm, gregz <ze...@comcast.net> wrote:
klem kedidelhopper <captainvideo462...@gmail.com> wrote:
On Feb 25, 12:37 pm, Jeff Liebermann <je...@cruzio.com> wrote:
On Sat, 25 Feb 2012 06:59:26 -0800 (PST), klem kedidelhopper

captainvideo462...@gmail.com> wrote:
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny

I had dinner with an acoustic engineer and asked about your hearing
aid problem.  He said it was possible and offered some hardware
suggestions, which I scribbled down somewhere.  However, he mentioned
an important point which you should consider if you build your own
device.  Since you can't hear much at about 3KHz, if you drive the
earphone with too much power, you risk creating additional hearing
damage.  You can't tell if the hearing aid is too loud (too high an
SPL).  Whatever you build, make sure that it has some kind of limiter
or compressor circuit to keep you from accidentally blowing out your
ear drums from a door slam or sudden loud noise.  He also agreed that
500-2800 Hz is about all you'll need for speech.
http://en.wikipedia.org/wiki/Sound_pressure
--
Jeff Liebermann     je...@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

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

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
Click to expand...
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
 
On Feb 26, 8:44 am, klem kedidelhopper <captainvideo462...@gmail.com>
wrote:
On Feb 25, 4:24 pm, gregz <ze...@comcast.net> wrote:





klem kedidelhopper <captainvideo462...@gmail.com> wrote:
On Feb 25, 12:37 pm, Jeff Liebermann <je...@cruzio.com> wrote:
On Sat, 25 Feb 2012 06:59:26 -0800 (PST), klem kedidelhopper

captainvideo462...@gmail.com> wrote:
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny

I had dinner with an acoustic engineer and asked about your hearing
aid problem.  He said it was possible and offered some hardware
suggestions, which I scribbled down somewhere.  However, he mentioned
an important point which you should consider if you build your own
device.  Since you can't hear much at about 3KHz, if you drive the
earphone with too much power, you risk creating additional hearing
damage.  You can't tell if the hearing aid is too loud (too high an
SPL).  Whatever you build, make sure that it has some kind of limiter
or compressor circuit to keep you from accidentally blowing out your
ear drums from a door slam or sudden loud noise.  He also agreed that
500-2800 Hz is about all you'll need for speech.
http://en.wikipedia.org/wiki/Sound_pressure
--
Jeff Liebermann     je...@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558

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

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

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
Click to expand...
someone mentioned using SoundCard in your PC
look at Daqarta's website:
<http://www.daqarta.com>
I think there are tools to check/verify your hearing using your own
system.
 
On Wed, 22 Feb 2012 07:07:16 -0800 (PST), klem kedidelhopper
<captainvideo462009@gmail.com> wrote:

I have known that my hearing has been getting worse over the last few
years. I recently had a hearing test to confirm this and compared it
to a similar test which was done 8 years ago. This confirmed my
suspicions. According to the most recent results my speech frequencies
are down about 30 DB more than previously noted. And I'm pretty
certain that 8.0KHZ and above is even worse. The tinitus also tends
exacerbate the problems further.

The test was rather interesting and informative and not unpleasant,
until that is the examiner switched into "salesman" mode. I realize
that these new aids have many new bells and whistles many that I will
never use. In any case, to make a long story shorter, 4000.00 is not
within my budget at this time. Unfortunately there is no money at this
time for anything.

SNIP
I'm semi retired now so I do have some time to fart around with
something like this if I had the appropriate information. According to
the test, I need to make up 55DB at 3.0 and 4.0 KHZ.
I really wouldn't mind carrying a box in my shirt pocket with an
earphone. Any help with such a project would be most sincerely
appreciated. Lenny
Click to expand...
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
 
On 2/25/2012 2:53 PM, Jeff Liebermann wrote:
On Sat, 25 Feb 2012 11:24:09 -0800 (PST), klem kedidelhopper
captainvideo462009@gmail.com> wrote:

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.
http://www.etymotic.com/ephp/mc5.html
$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:
http://reviews.cnet.com/8301-19512_7-10281062-233.html
http://itunes.apple.com/app/soundamp-r/id318126109
http://itunes.apple.com/us/app/tinnitus-help/id382593362
http://www.ind-technik.eu/software/tinnitushelp/
http://www.ind-technik.eu/software/hearinghelpforiphone/
There are probably other apps.

What we need here is a cheap DIY shotgun Microphone.
Click to expand...
Mikek
 
On 2/26/2012 6:15 PM, amdx wrote:
On 2/25/2012 2:53 PM, Jeff Liebermann wrote:
On Sat, 25 Feb 2012 11:24:09 -0800 (PST), klem kedidelhopper
captainvideo462009@gmail.com> wrote:

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.
http://www.etymotic.com/ephp/mc5.html
$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:
http://reviews.cnet.com/8301-19512_7-10281062-233.html
http://itunes.apple.com/app/soundamp-r/id318126109
http://itunes.apple.com/us/app/tinnitus-help/id382593362
http://www.ind-technik.eu/software/tinnitushelp/
http://www.ind-technik.eu/software/hearinghelpforiphone/
There are probably other apps.

What we need here is a cheap DIY shotgun Microphone.
Mikek
Click to expand...
Here's an 8" parabolic Mic that could be used for watching tv.
http://www.amazing1.com/accoustics.htm Down Page.
 
On 2/27/2012 11:50 AM, gregz wrote:
klem kedidelhopper<captainvideo462009@gmail.com> wrote:
On Feb 25, 4:24 pm, gregz<ze...@comcast.net> wrote:
klem kedidelhopper<captainvideo462...@gmail.com> wrote:
On Feb 25, 12:37 pm, Jeff Liebermann<je...@cruzio.com> wrote:
On Sat, 25 Feb 2012 06:59:26 -0800 (PST), klem kedidelhopper

captainvideo462...@gmail.com> wrote:
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny

I had dinner with an acoustic engineer and asked about your hearing
aid problem. He said it was possible and offered some hardware
suggestions, which I scribbled down somewhere. However, he mentioned
an important point which you should consider if you build your own
device. Since you can't hear much at about 3KHz, if you drive the
earphone with too much power, you risk creating additional hearing
damage. You can't tell if the hearing aid is too loud (too high an
SPL). Whatever you build, make sure that it has some kind of limiter
or compressor circuit to keep you from accidentally blowing out your
ear drums from a door slam or sudden loud noise. He also agreed that
500-2800 Hz is about all you'll need for speech.
http://en.wikipedia.org/wiki/Sound_pressure
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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

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

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

I got a horn for my birthday !!

Greg
Does it look like this one?
Click to expand...
http://3.bp.blogspot.com/_T6-yynP3gQo/SejU7SG_LZI/AAAAAAAAAD4/FHVQyZ9vrX4/s1600-h/MegaHearingAid.jpg
Mikek
 
klem kedidelhopper <captainvideo462009@gmail.com> wrote:
On Feb 25, 4:24 pm, gregz <ze...@comcast.net> wrote:
klem kedidelhopper <captainvideo462...@gmail.com> wrote:
On Feb 25, 12:37 pm, Jeff Liebermann <je...@cruzio.com> wrote:
On Sat, 25 Feb 2012 06:59:26 -0800 (PST), klem kedidelhopper

captainvideo462...@gmail.com> wrote:
I'm embarrassed to admit that the Harbor Freight one for 12.00 really
intrigues me. It says that it is tone, (whatever that means) and
volume adjustable. I just wonder if it could possibly have some kind
of a high frequency pre emphasis circuit in it. And since I haven't
been able to find my father's old ones around here yet buying this
thing might prove to be an interesting experiment, or a waste of
12.00, plus S& H for a worthless POS). Well it's not 1200.00... Lenny

I had dinner with an acoustic engineer and asked about your hearing
aid problem. He said it was possible and offered some hardware
suggestions, which I scribbled down somewhere. However, he mentioned
an important point which you should consider if you build your own
device. Since you can't hear much at about 3KHz, if you drive the
earphone with too much power, you risk creating additional hearing
damage. You can't tell if the hearing aid is too loud (too high an
SPL). Whatever you build, make sure that it has some kind of limiter
or compressor circuit to keep you from accidentally blowing out your
ear drums from a door slam or sudden loud noise. He also agreed that
500-2800 Hz is about all you'll need for speech.
http://en.wikipedia.org/wiki/Sound_pressure
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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

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

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
Click to expand...
I got a horn for my birthday !!

Greg
 
amdx <amdx@knologynotthis.net> wrote:
On 2/25/2012 2:53 PM, Jeff Liebermann wrote:
On Sat, 25 Feb 2012 11:24:09 -0800 (PST), klem kedidelhopper
captainvideo462009@gmail.com> wrote:

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.
http://www.etymotic.com/ephp/mc5.html
$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:
http://reviews.cnet.com/8301-19512_7-10281062-233.html
http://itunes.apple.com/app/soundamp-r/id318126109
http://itunes.apple.com/us/app/tinnitus-help/id382593362
http://www.ind-technik.eu/software/tinnitushelp/
http://www.ind-technik.eu/software/hearinghelpforiphone/
There are probably other apps.

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

http://www.atlantahearingaidcenter.com/
 
On Sun, 14 Apr 2013 21:24:35 -0700 (PDT), wilianswilim@gmail.com wrote:
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.

http://www.SLIME-BALL-SPAMMER.url/
Click to expand...
You should better start with a speaking aid.
Your spam is almost un-readable.
 
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