Hifi Hearing Aid

[ruffrecords]

Since turning 65 I have noticed an obvious deterioration in my hearing, particularly the high frequencies. It is getting to the point where I regularly cannot make out what people are saying or I simply mishear it. I dread the thought of tinny lofi hearing aids so I am wondering if there is anything like a hifi hearing aid available?

Cheers

Ian

 

[ln76d]

Not exactly know what's lofi hearing and hifi hearing, but usual these graphs are not so far from the real world:

http://static.wixstatic.com/media/9d73b1_5b71874038484537b8a50f37d6c5c3de.gif
http://www.nonoise.org/library/handbook/fig27.gif
http://www.roger-russell.com/hearing/hearing4.jpg

If you could explain a little, i can ask my girlfriend , she's audiologist.

 

[ruffrecords]

If you could explain a little, i can ask my girlfriend , she's audiologist.

I find it hard to believe that conventional hearing aids include a microphone and earpiece that are capable of spanning the entire audio spectrum from 20Hz to 20KHz  and neither will they do it at low distortion. I suspect all they do is boost the higher frequencies necessary for speech intelligibility.  I suspect their bass response is sadly lacking. What I would like is something that corrects for the response errors in my hearing but has the overall frequency response and low distortion you expect from hifi.

Cheers

Ian

 

[PRR]

I will assume you have had a good ear exam. Old men go incurably deaf, but there are some less-common causes which can be treated. (I went as far as an MRI of my head, but I think this was bad medical advice.)

Have you had an ear-curve taken?

Have you tried a good modern hearing aid for daily wear?

True, the usual aid is intended to improve speech intelligibility, not so you can mix cymbal overtones and synth squeegies, or even shrill singers, with the rest of the band.

> corrects for the response errors in my hearing

If you fully correct the highs, you burn-out what little is left of your treble nerve cells.

(And also enormously increase power demand: note 40db-80dB loss in the 3KHz to 8KHz range.... this is impractical.)

Low freq response is not difficult, though bass output level again gets into power tradeoffs. The practical compromise is to note that most old men hear bass quite well, are not complaining about missing the sound of thunder or distant trucks, and let ambient bass pass around the earpiece. The main complaint is lack of speech intelligibility ("everybody mumbles"). 95%(?) of speech intelligibility is in the 300-3KHz band. A typical (most men) curve must give little boost at 300Hz, rising to considerable (~~20dB) boost at 3KHz.

3-6K adds sibilants, but it gets difficult to fight the 30dB(!)/Oct curve there. Which is only getting worse every few years, so a monster boost is only a short-term investment.

I will attach curves for me and my dad. My curve is some years old, his is recent; I noted ages. His is doc-plotted; mine is sketched from a more detailed plot. I suspect my 3KHz Right is well down since this test.

My 25dB/Oct slopes will be a severe EQ; not just to get the slope but to align the corners so the compensation does not peak/dip. Corners that sharp, on an ear which is aging, may have to be re-trimmed every few months for any semblance of "flat". Over the years this gets worse.

Compensating Dad's 70dB loss from bass to 6KHz, and 45dB/Oct 1K-2KHz, is really awkward.

FWIW, Dad found the EQ in Windows Sound Card and says it helped him enjoy music in headphones, even though it can't be more than nominal 20dB.

 

[micaddict]

If you fully correct the highs, you burn-out what little is left of your treble nerve cells.

^
This.
But the story is seldom told.


Also, in-ear devices are far from ideal IMO.
Yes, they are practically invisible ...

 

[PRR]

me> enormously increase power demand: note 40db-80dB loss in the 3KHz to 8KHz range.... this is impractical.

Let's figure the power required. Say a good home speaker at 88dB/Watt at listener needs 100W to cover musical peaks. How much of this is above say 3KHz? Average, very little. But a tweeter is a differentiator and will have severely spiked waveforms with high peaks. On classical, bi-amped, we might get by with a 10W tweeter amp above 3KHz. But today's bi-amped powered monitors will put 1/4 to 1/2 of woofer power to the tweeter. Partly because of the economics of chip-amps and secondary channel, but mostly because modern music is bright and tweeters should not clip.

Say tweet power is -6dB of woof power, for a young ear.

My 3KHz was 30dB down a few years ago. Tweet-power is (-6)+(30)= +24dB. Tweet amp should be 200X the bass amp power! (And bi-amping loses its point, so assume one amp.)

iPod earbuds do with 1mW what a speaker does with 1W. So reference 100W becomes reference 100mW. 30dB gain by sticking the speaker in your ear.

If we don't even try for 16KHz response, transducer design can be aimed for a resonance (broad on the low side) at 5KHz-8KHz. This can gain 10dB sensitivity, 40dB gain over room speaker.

100W -40dB +24dB ... we need 2.5 Watts in the earphone. This today may be a pocket-size amp, but at a concert or mix-session the battery life may be impractical.

Decades older, my Dad needs another 40dB at 3KHz, 10,000X power, 25 KILO-Watts! I don't have that much power at my house meter.

(40dB at 1.5KHz would be less impractical, but still in the Watt-size amp, just to cover ~~5/8 of the youth-audible spectrum.)

 

[JohnRoberts]

+1 to hearing test, but you can probably mess around with a graphic EQ and headphones to determine what sounds good-better to you (maybe tweak each ear differently).

+1  too much boost can accelerate deterioration of already damaged stereocilia (specialized hairs) that can bend and break.

They make low power class D amplifier chips smaller than my pinky finger nail that make a couple watts and sip battery power.

Maybe roll your own from some ear buds designed for monitor use during live performances.

JR

 

[thermionic]

If you trawl the UK AES archives, you might be able to find a recording of Brian Moore's lecture (I can't find it on a quick search - but there were tens of audio recordings on it a while back). He talks about hearing aids (apparently, the top ones when he gave lecture a few yrs back were 14-bit).

If you can't find it, see if they'll let you have a copy - someone will have an MP3 somewhere. It would be a small-ish MP3. It'll be of general audio interest as well.

Best of luck!

edit - it you can't find it you could always drop the man himself an email: http://hearing.psychol.cam.ac.uk/Biogs/bmbiog.html

In fact, you could just ask Moore if he can give you some pointers towards high-spec hearing aids. I'm sure he'd be helpful, especially if you give him a little background on you being an engineer.

 

[ln76d]

I find it hard to believe that conventional hearing aids include a microphone and earpiece that are capable of spanning the entire audio spectrum from 20Hz to 20KHz  and neither will they do it at low distortion. I suspect all they do is boost the higher frequencies necessary for speech intelligibility.  I suspect their bass response is sadly lacking. What I would like is something that corrects for the response errors in my hearing but has the overall frequency response and low distortion you expect from hifi.

Cheers

Ian

Rather i was thinking about something different than cyborg
Maybe there are some methods (doubt it will bringa back proper hear) which could prevent even a little further loss.
Anyway, technology of hearing aid evolved, DSP is quite popular, but for that i think you have still much time
There's much more methods of tests which  can precise causes of  loss.
Most important is to find good doctor and good audiometrist, something which you will probably not find in hearing aids sell centers.

 

[ruffrecords]

Thank you everyone for the thoughtful replies.

Cheers

Ian

 

[abbey road d enfer]

Since turning 65 I have noticed an obvious deterioration in my hearing, particularly the high frequencies. It is getting to the point where I regularly cannot make out what people are saying or I simply mishear it. I dread the thought of tinny lofi hearing aids so I am wondering if there is anything like a hifi hearing aid available?

Cheers

Ian

I have also an hearing problem; I cannot make out what some people say. I noticed that listening to Nigel Farage, Boris Johnson, Donald Trump, Marine Le Pen, Norbert Hofer, and a few others.
After having tried several equalizers, I think the only one that could do the job is that one
https://en.wikipedia.org/wiki/GAU-12_Equalizer

 

[JohnRoberts]

Since turning 65 I have noticed an obvious deterioration in my hearing, particularly the high frequencies. It is getting to the point where I regularly cannot make out what people are saying or I simply mishear it. I dread the thought of tinny lofi hearing aids so I am wondering if there is anything like a hifi hearing aid available?

Cheers

Ian

I have also an hearing problem; I cannot make out what some people say. I noticed that listening to Nigel Farage, Boris Johnson, Donald Trump, Marine Le Pen, Norbert Hofer, and a few others.
After having tried several equalizers, I think the only one that could do the job is that one
https://en.wikipedia.org/wiki/GAU-12_Equalizer

I'm afraid in the US they would never approve that equalizer firing >3,000 rounds per minute unless you limited it to an 8 shot clip. 

I find the FF button on my DVR helps me skip over unpleasant commentary (which is 99.9% of it).

JR

 

[ruffrecords]

I'm afraid in the US they would never approve that equalizer firing >3,000 rounds per minute unless you limited it to an 8 shot clip. 

There is also the problem of getting 3000 deserving people together in one place so they could be equalised in one go. Mind you it would be quicker than a Lee Enfield and one at a time.

Cheers

Ian

 

[sahib]

I have also an hearing problem; I cannot make out what some people say. I noticed that listening to Nigel Farage, Boris Johnson, Donald Trump, Marine Le Pen, Norbert Hofer, and a few others.

It sounds to me like blessing  rather than a problem.

 

[ricardo]

In the 80's, I was peripherally involved with hearing aid design.

There is a HUGE range of hearing defects and one very common one is that the patient hears stuff distorted rather than just at a reduced level.

The exciting development in those days was that DSP could help reduce perceived distortion.  I've lost touch with developments but it is worth talking to an audiologist about this.

Certainly the technology to do this is a LOT cheaper than 30 yrs ago.  A modern mobile phone or MP3 player with ear buds has all the hardware required including the DSP capability.

 

[abbey road d enfer]

There is a HUGE range of hearing defects and one very common one is that the patient hears stuff distorted rather than just at a reduced level.

Absolutely. the hearing process/stapedian reflex/brain can deal with 40dB anomalies in sensitivity, to the point that the patient ignores he is partially deaf. Indeed distortion is the big issue; that's why most of the hearing aids do little to solve the problems, since they just boost the frequencies that are de-sensitived, increasing distortion.
I'm not sure there's any practical implementation of distortion compensation in current hearing aids; it seems they are restricted to "frequency shaping,  noise  suppression,  multiband  amplitude  compression,  and  frequency  dependent interaural  time  delay  algorithms".
This article (dated 2001)
http://www.audiologyonline.com/articles/digital-hearing-aids-hype-hoax-1221
shows that at the time, distortion compensation was not included in the design brief.
A more recent (2010) does not seem to offer more "The DSP implementation is manufacturer dependent. In general, it performs compression/expansion by band, positive feedback reduction, noise reduction, and speech enhancement."; it "It also processes directional information and can generate its own signals to help improve fitting a hearing aid to a patient." "It also processes directional information and can generate its own signals to help improve fitting a hearing aid to a patient." (in https://www.maximintegrated.com/en/app-notes/index.mvp/id/4691)
Page 3 of this document seems to state quite well the status of current hearing aids
http://www.intricon.com/assets/documents/uploads/Overtus_ProductFeatures.pdf
Current litt on the subject seem to indicate that your involvement in distortion compensation may have been an isolated effort that did not permeate the mainstream.
DSP distortion compensation in loudspeakers (horns) has been a fad in the early 2000's, advocated by Wolfgang Klippel; daunted by the complexity of the problem, he finally set out to develop the loudspeaker development/control platform bearing his name. It seems the data-crunching power needed for the task exceeds the resources of the most powerful DSP platforms commonly available.

 

[ricardo]

Current litt on the subject seem to indicate that your involvement in distortion compensation may have been an isolated effort that did not permeate the mainstream.

Maybe its time to develop a smart phone app for this.

No one finds it strange anymore to see healthy youngsters permanently connected to their phones via their ear buds.  :

But I've only joined the 21st century (bought a smart phone) this year.  8)

In the 1990's I did a lot of theoretical & experimental work on speaker measurement and EQ.  The computing power (and particularly good codecs) were far too expensive in those days for the target market.

When I re-emerged from the bush in 2005, I find that the cheapest PC or phone has power well beyond my 1990 dreams.  So 30 yrs later, I'm able to put into practice some of these dreams .. even as a professional beach bum.

 

[ruffrecords]

Current litt on the subject seem to indicate that your involvement in distortion compensation may have been an isolated effort that did not permeate the mainstream.

Maybe its time to develop a smart phone app for this.

No one finds it strange anymore to see healthy youngsters permanently connected to their phones via their ear buds.  :

But I've only joined the 21st century (bought a smart phone) this year.  8)

Isn't the weak link in this chain the microphone?

Cheers

Ian

 

[micaddict]

So how about a DIY hearing aid?  8)

Won't be small, though. 

 

[ruffrecords]

So how about a DIY hearing aid?  8)

Won't be small, though. 

Yes, I had thought about a crossed pair of ribbons strapped on top of my head plus a decent pair of cans and a DIY amp/EQ. No tubes this time though.

Cheers

Ian