Question? Could some1 build a Digital CIC DIY style?

Say I wanted to make my own Hearing Aid, A digital one at that. Say I had the DSP that did everything a High End Belton, High End Siemens, Starkey, or WIDEX.

Say the DSP is capable of, Multichannel 1, 2, 4, 6 or 8 WDRC compression with fully programmable crossover frequencies and time constants 16-band graphic EQ

Say it had, 32 kHz and 16 kHz sampling rate; 16kHz or 8kHz bandwidth

Lets throw in, 128-band Adaptive Noise Reduction ANR 3.2

Say, Real Ear hearing aid feedback path modeling

and lets not forget, 20-bit high quality audio precision

Now say I had a DSP with all those Features and So many more… For example; You pick your Favorite Digital Hearing Aid around $2K and Up Probably closer to the High end models, and this DSP might just have everything it list on that High end Aid.

OK, So you have a DSP and You have The DSP Programmer, you know to talk to the DSP the company might even know to tell you where to purchase such, or Hi-Pro or Noah link System and All the Software the DSP Needs to Program the Hearing instrument “DSP”

Now you have the DSP and the Stuff to link it to a PC, and you have the Audio-gram to tell the DSP what it needs to do for the person.

You have the Microphones, Front & Rear mics. Yes the DSP does 2 and a Telecoil.
You have the Receiver/Speaker.

Now Comes the Shell you need to put all of these Tiny parts inside it.
You’ve decided to go with CIC, for each ear. After talking to an Audiologist, he says yes you can use the CIC.
You have your In Ear Impressions…
Now comes a very difficult part. “I use Difficult very loosely”
How Do I Make a Shell… Well, I don’t because it would cost more for me to buy the Acrylicast or Klarsil or something of the sort. All the other stuff I would need to make a Hollow Shell, “I would like VERY much to know how that is done though!”
So turns out what you thought was hard isn’t at all, because you have the impressions of your Ears and as you know it there’s only about 15-20 Companies that make Hearing Aid Shells for the 90-120 Hearing Aid Companies.
So you send off your Ear Impressions and they charge you a small fee to make the Shell for both ears they also make the battery doors and the Top plate, they bore a vent if you like and a Sound chamber also. The Door to the battery and the Plate are left unattached from the Hollow shell part. All for under $80

Now since you have all of theses parts and your very handy with a soldering gun even with very small parts you have knowledge of Electronics, you also have the Wiring Diagram to put it all together. All the software the Pros Use.

So let me get around to the Question already!

Why couldn’t one do such if you had all of this stuff? What’s stopping someone from doing a DIY Hearing Aid??

Could this be done? :cool:

1 Like

A simple answer yes it could be done :slight_smile:

But there are many buts :slight_smile:

Most hearing aids are medical devices as such has to complied to certain rules, making a device that complies to all of this could be difficult. Not knowing all rules for hearings aids so I can’t clarify them.

Since you want to make a CIC all your electronics (the DSP, mics, telecoil, receivers and wents) has to fit inside and be able to run on a small battery size 10, this I think would be one of the biggest problems i real life.

Then there are the dsp software how to compensate for a hearing lose, that kind of fitting rule to us:e half gain rule, NAL, DSL … or some home made one

There properly going to be a few more buts, but I looking forward to see your hearing aid, it looks very promising on the screen at least.

The MDA rules wouldn’t apply to anything home made, only those things that you want to sell on to a consumer.

Of course if you have the technical know-how and all the equipment to build something, you don’t need a professional to do it. But I can’t see how this is different to any other industry.

I suppose it could be done.

You certainly can already buy all the bits you need - for an ANALOGUE aid - from someone like TONDI in Estonia.

You could then rip out their chip and put yours in.

But then you could also build a helicopter in your garage from old bicycle parts, or a hunting rifle from that old plumbing tubing you have lying around.

Or maybe a tiny notebook computer from old computer parts … hey, who needs an iPod?

Can you REALLY imagine more than a handful of people making their own in-the-air hearing aids?

Hearing loss is usually an ailment of the elderly … who might not have the eyesight, dexterity or drive to want to BUILD hearing aids!

As for all your ‘say we have this and that and that’ … err THAT’s the difficult part, NOT the shell. This super chip you describe can only come from someone like Phonak … who probably won’t talk to you … and even if they did, would charge say $500 for it.

And then you have the integration of the mikes, speaker, chip, programming software etc. And the mechanical suspension. And how about feedback control? Can you mount all the bits properly to prevent INTERNAL feedback inside the shell body?

Oh yes, whose software will you use? How will you get it? How much will it cost?

Forget building your own: simply hone your negotiating skills and persuade someone to fit you a REAL aid at a discount price.

Right on.

BTW for a digital instrument you would have to author the firmware as well.

If you have the skill and knowledge to do all of this by yourself, you probably have and are willing to part with the full rack rate amount of money for a pair of high end instruments rather then invest this amount of time.

There is a step in between, where you buy a commercial chip from gennum that comes with the firmware & circuit board artwork and make a BTE with commercially available shells, mics, receivers. You bite the bullet and buy enough material for 100 instruments, then sell the remaining 98 of them for $100 on the internet, which more then covers your out of pocket expenses.

What do you say ed? I’ll buy 2 or 3 from you!

Let me start off by saying, I’ve been working on this since Nov-Dec 08’
I’ve researched this and till about Mar. 09’ with no luck finding a DSP to use in a Hearing instrument application I kind of gave up on it… You know how something festers you in the back of your mind until you just cant stand it and you know you need to do something about it? Well this was really making me want it more… I knew there was a company out there that makes the DSP for theses hearing Aids. I know that Belton was a brand, therefore they had to have someone making the DSP for them. Just as Phonak or Starkey. Theses our name brands. For Example: Ultimate Ears uses something like KNOWLES ACOUSTICS for the speaker/Receiver and tattoo there UE on the casing. Even though they dont make them.

The Feedback control your asking about, well, The Feedback Path Measurement Tool uses the onboard feedback cancellation algorithm and noise generator to measure acoustic feedback path of hearing aid during fitting. Real-ear measurements enable accurate analysis of the hearing aids feedback path in the wearer’s ear and enables customization of hearing aid fitting to in-ear acoustics.
Adaptive Feedback Cancellation (FBC 3)
Real Ear hearing aid feedback path modeling
To add, AFC 3 estimates the portion of the hearing aid output signal that is due to feedback and adaptively cancels the feedback from the signal path as using a LMS-based phase cancellation algorithm.
Up to 30dB of Added Stable Gain with the use of a 40-tap FIR filter. The Added Stable Gain on AFC3.2 was bench-marked to be greater than most competitive products, which were measured at the National Research Council, Canada. Furthermore, an innovative approach to entrainment management on the AFC 3.2 enhances the efficacy of the product without injecting any distortions to the signal path and offering imperceptible removal of feedback in most environments while maintaining leading edge adaptation speeds.

About the “Mikes” (Mic)(Mics) I thought I added this… Well I must have not mentioned it was capable of, Automatic Adaptive Directional Microphones (ADM 2.0) &
directional processing.
ADM 2.0 is a two-microphone processing scheme for hearing aids. The ADM automatically reduces the level of sound sources originating from behind or from the side of the hearing-aid wearer by adjusting the null in the microphone polar pattern to minimize the noise level at the output of the ADM. The automatic steering of the null provides improved signal to noise ratio. The polar patterns change with the nature and location of the noise sources. The rear mic processing is automatically powered-off when not required to save current and offer extended battery life.

Its been a long time in the making and I received my DSP Programmer today along. I’ve had the software for about a month now. This software is well known in the Hearing instrument industry.

90% of Microchip companies provide you with software for there products. This is the case with this place.
I will have the impressions later this week and they will be sent off to a well known company who makes shells for alot of store fronts.

I Do have pictures of the DSP’s Size of it and the DSP Programmer. If anyone wants to see it PM me.

If you want to know anything about this project I will be glad to let you know! I am hoping to receive the components latter this month.

The CIC Shells have a fast turn around time. I hope to get some photos up somewhere but not sure where… any suggestions on pics? Or any other suggestions.

Oh and by the way the DSP is very very very Its ridicules how cheap it is! Its so cheap It makes me sick how much they charge you for this!
When its said and down I will have out of my own pocket. Under $350.00 and thats for 2 TWO ears. Shells and all!:smiley:

Your close but Nope.
Samples my friend Samples.:slight_smile:

Here is the DSP

If anyone is an Audiologist reading this thread and has some Positive information I would love to hear from you.

I am doing this for my Dad who can’t afford to buy hearing aids, He lost much of his hearing in his Right Ear in Vietnam war. His Left ear is better but the last test he had, the Doc said he needed one for each ear.
He said if I have to wear theses things then I want the smallest I can get.
His words were much more “Choice” than this… I always say He lost his hair and hearing over there.

I have worked hard to find this info I’ve found so far. It didn’t start coming together up until a few months ago…
I’ve gotten almost everything Donated or Samples. I would also like to add some things are extremely discounted. Such as the Professional CIC Shells, and all the Impression Material. I am still going to attempt to make my own Shell but I will also order the CIC shell.
The Acrylicast or Klarsil or something of the sort will be here shortly.

You have NO IDEA how hard it is to find this stuff when you don’t have a Clue to what its called!!! Try finding something in a Hay stack but you don’t know what it is your looking for! I think Mythbusters proved you can find a needle in a haystack fairly easily. Replace the Needle with ( ? ‘shrug’ :mad:) and look for it.

Any assistance would be So much very Grateful

I appreciate your spirit. However, I do think that HA prices are likely to break lower before you will be able to construct a useable, reliable model. I would look toward the emerging internet suppliers such as New Sound and try to work with them as they develop their retail businesses. Their samples may be more directly useful…

I haven’t head of them… I Already have the DSP’s about 12 different versions with different features. And I received the DSP Programmer to interface with the PC through USB Today at 10AM It was shipped yesterday.
I have all the Software to Program the correct audio gram.
I am waiting the Transducers and Receivers which will be here soon.
The Ear Mold Company is located in the US where I am.

The Cost of the Professional CIC Shells and battery door vent and so on are at the cost of $20 Per Shell. =$40.

I’ve only dealt with US and Canada companies.:slight_smile:

I read your Reply today and you said,

“As for all your ‘say we have this and that and that’ … err THAT’s the difficult part, NOT the shell. This super chip you describe can only come from someone like Phonak … who probably won’t talk to you … and even if they did, would charge say $500 for it.”

I did some digging in Google and I came up with Phonak DSP, I’m not sure what model they use this in but I know its one they use. Ill post the Link that lead me to believe this is one DSP they use BELOW.
However you can buy the “BelaSigna Audio Processor 300/200/250” @ You can Purchase the BelaSigna 300 DSP for $12.00 at the LINK above. Not $500. :slight_smile:

It seems The price of this DSP was a bit cheaper than the one I am using… That is if I bought it and didn’t receive it as a Sample. Mine is $27.

Im assuming you can use the Hi Pro to program this DSP. I may play around with this after I get the setup I am working on now completed.


newsound is chinese company, very tiny…

At whole sale pricing their princing are not to low compare to trad. manf (export)

more competition is good for everyone

Shipping is very cheap. I work at FedEx with a 75% discount on shipping anywhere in the world.
It would have been about $80.00 to overnight it. It cost me $21. using my FedEx account.

If you are determined to build rather than buy, then I strongly recommend that you build a “breadboard” first, pocket size, with all the components in place and the firmware loaded. You can find breadboard materials at FrysElectronics stores or their website. Here is a link to breadboards The breadboard will show you all the problems that you have not yet solved and you will be able to rearrange components or modify the firmware parameters as needed to get it working. Then consider making a much smaller version that will fit in one of the ear shells. I would think a BTE shell would give you a lot more lattitude to arrange components.

If you were to attempt to create the tiny version on the first pass, the probability of it working would be very close to zero and it would be extremely difficult to debug and / or modify.

Right now I am waiting on the Wire to get here from Denmark. Which is the only company I’ve found who makes this size wire. I believe its also used in Headphones like UE and Shure and others… It should be here tomorrow or Sat.
The Mics and Receivers will be here Around Sept. 9th ish…

I will Solder the Mics and Receiver to the DSP along with the Telecoil along with the Push buttons. After talking with the Knowles tech team I will decide on Tube Lengths. The Mics will not need tubes.

After getting everything soldered and all ready to go I will install it in the Shell.
I WONT attach the Top to the Lower shell before I test to make sure it powers and works.


Tell your dad to call the VA and find a local VA worker who can assist with filing a VA-Form 21-526 Veterans Application for Compensation and/or Pension.

If military service is the likely cause of his hearing loss then the VA will pay for his hearing aids and for the batteries too.

He Told him they wouldn’t pay for both ears and they wouldn’t pay 100% of it… Do you know if theres any Weight to this story?

Tonight I made his Impressions Made and They will ship tomorrow to the Company making the CIC Shells.

I should have them back about the time the Microphones and Receivers Show up. Crossing Fingers!

Telecoil Whats is the best to use? I have a few different Versions to choose from… :eek:

The first up for is 5100 series passive telecoils feature a polyurethane coating for optimum environmental protection as well as a vast array of electrical and mounting options to choose from.

Second, SMT passive telecoils feature the same electrical performance benefits as the 5100 series in a package designed for surface mount reflow installation.

Third, Active Telecoil: Amplified hybrid circuit provides a telecoil with superior RFI suppression.

All the info about the Different TCoils, you can find at

ALSO where can I find a Supplier for theses Switches? I dont want to purchase any more then 6 to 8…
INFO: 2900 - Ultra Miniature Push Button
Pushbutton overtravel design enables electrical contact prior to full pushbutton travel for superior mechanical actuation.

There made by KNOWLES but to order theses you have to purchase 25 I believe… Anyone have any suggestions?