Hearing Aids PLUS in ear monitor system
Jun 13, 2015 at 4:43 PM Thread Starter Post #1 of 3

cardocpdx

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Hello all,
I have a desire for a product that may exist but I cannot find.  Perhaps someone on here can assist.
 
What I want is a hearing aid "package" that will also function as a true high fidelity personal sound system.  I currently wear high end digital hearing aids of the "receiver in the ear" sty;e.  The body of the aid is placed "behind the ear".  Each aid contains 2 microphones (one omni and one directional).  The microphone outputs are then sent to a DSP processor that attempts to identify speech content, reduce noise, eliminate feedback, cancel wind noise and about 10 other things.  In addition I wear (on a lanyard) a remote that also contains a bluetooth interface that interfaces with my phone providing both hands free phone function and stereo music streaming.
 
This hardware is awesome and does more that you can imagine to improve my interaction with the world.  The sole shortcoming is the music streaming function.  The in canal "receivers" (the speaker if you will) are tiny.  This combined with conserving electrical power causes the system to not even try to reproduce frequencies below about 300 Hz.  Music sounds like listening to a transistor radio from the 70's.
 
Having the hardware in the ear makes it impossible to wear, earbuds.  Feedback issues make it inconvenient to try and utilize "on the ear" or "over the ear" headphones.
 
The answer is some mid grade in ear monitors, except there is no way that the hearing aids can put out enough power to drive them.  What I envision is a body worn WIRED system that interfaces (and powers) with the hearing aids, accepts the output of them then mixes with music and delivers to the mix to in ear monitors.  The dream system would have an on-board digital music player (MP3 if you must) and DSP to equalize and compress the music to match my hearing curves.  Bluetooth phone function in wanted too.  Final want is a DSP head model to convert stereo to Binaural.
 
Does such a thing exist?  If not who wants build one.  I volunteer to do the testing for free (BTW my 8 to 5 gig is test engineer, automotive, including NVH).
 
Thanks for reading, once my NOOB status is lifted I will post another long rambling request in the IEM forum.
 
Jun 14, 2015 at 12:01 AM Post #2 of 3

ProtegeManiac

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You'll have to ask any of the haring aid manufacturers for that, and some of them manufacture IEMs, like Westone - they might get you a hearing aid DSP that they can program to work with one of their CIEMs.
 
Alternately, if you can contact the audiologist or manufacturer who programmed the DSP on your hearing aid, you can ask for the correction curves applied. Then, when you order a CIEM, make sure you get one that 1) you can easily drive with a smartphone and 2) you can get a copy of the response curve.

Then, download NeutronMusicPlayer for your smartphone (Android or iOS), apply as best you can the correction curve on its parametric EQ (maybe get some help from your audiologist, or you can Google "How to EQ" to understand how to work a parametric EQ with variable center freq and Q-Factor) and dialing back if you get distortion. Take into account the latent response of the CIEM, so for example it already has a plateau in the bass region, even if you might have a correction curve in those frequencies, then don't apply anything there anymore (or maybe dial back, in case the added bass can add some harm to your ear drums).
 
Past getting a customized DSP from Westone, try the 1964Ears Adele CIEMs - they have an airvent to relieve air pressure caused by pressurized bass frequencies that might do even more damage in your ears.
 
Jun 14, 2015 at 2:02 AM Post #3 of 3

cardocpdx

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Thanks for the reply. As far as I can determine Westone does not actually make hearing aids (unless they do it under another brand name).  They do have a wide range of "assisted hearing devices" but the key here is having the microphones and speech tracking DSP* functions of a modern hearing aid as the primary function.  Perhaps I was unclear but the goal here is an all day every day system to REPLACE my hearing aids with the added feature of decent fidelity music.  My ears are wrecked so super high end gear is not required but I'd like to get the most use out of what is left.
 
I use android apps that do an adequate job of curving and compressing music tracks to match my ears for dedicated music sessions using a set of non custom IEM's.  The problem is I can't wear them at work, or in the grocery store as I can't simply pull one out and converse with someone.  I have to remove the cans, fish in my pocket for the aids, insert the aids and power them up.  After 3 or 4 repetitions of this the aids stay in and I am music deprived for the rest of the day.
 
* This is hard to explain and has no bearing on this conversation but here goes:  Your healthy ear has about 20,000 hairs in the cochlea.  Each and every one has a slightly different center frequency and a different "filter" slope.  Every hair has a nerve ending that transfers information to the brain.  My cochlea has, perhaps, 4000 hairs.  Healthy ears give your brain enough "resolution"** to converse with someone in a restaurant because for each tiny bit of speech there is a "Perfect" hair that is sending a signal that matches the pitch of the speakers voice.  I can not differentiate a single voice in a random noise environment.  Eq and compression help some but a modern hearing aid attempts to focus on speech and not amplify the background sounds when speech is present.  The technology is far from perfect but it is impossible to "give up" once you've experienced it in a quality hearing aid.
 
** The best analogy I can come up with is this; think of that horrible web page you ran across where someone had superimposed pale yellow italic text over a field of flowers.  At web standard of 96 dip you can read it (but it is a struggle).  Do a screen capture and reduce the size to 33%.  Open the resulting image.  No amount of zooming (amplification) or fiddling with the brightness and contrast (Eq) will allow you to read it.
 
Thanks again for the ideas.  I have considered contacting a couple of the aid manufacturers and seeing if they are interested in supplying boards with "line out" instead of sending the signal to a speaker.  I just want to be sure I'm not reinventing the wheel.  
 

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