
LoCHAid – An ultra-low-cost, affordable and accessible hearing aid device - ArtWomb
https://www.biorxiv.org/content/10.1101/811828v1
======
Uhrheber
This is basically how the first transistorized hearing aids in the 60s worked.

Zero innovation, and an implementation that wastes lots of power. Why would
you use a volume potentiometer at the OUTPUT of the amplifier? It turns most
of the output power into heat. And why would you use a stereo amplifier and
short the two channels together to get a mono amplifier?

You can already buy (in ear) hearing aids for less than $3 from China. A
little bit more money even gets you rechargeable ones.

Also: Even in developing countries, more and more people have smartphones. In
fact it might be easier to get a smartphone there than a professional hearing
aid. There are apps that act as a hearing aid, taking the sound from the
microphone, amplifying and filtering it, and sending it to the headphone
output. Unlike with this project, the use can individually adjust the
frequency response to his hearing.

~~~
dreamcompiler
Smart phones make lousy hearing aids. First the microphone needs to be in your
ear for directionality, not on the phone. Second, phones don't have realtime
operating systems, so latency and dropouts can be a problem unless you program
them _very_ carefully. And even then it's not 100% predictable what's going to
screw up the signal path.

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bhattisatish
The actual paper:
[https://www.biorxiv.org/content/biorxiv/early/2019/10/21/811...](https://www.biorxiv.org/content/biorxiv/early/2019/10/21/811828.full.pdf)

The github repository containing the STL files:
[https://github.com/bhamlalab/LoCHAid](https://github.com/bhamlalab/LoCHAid)

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anotherevan
The IQBuds from [https://www.nuheara.com/](https://www.nuheara.com/) have been
a godsend for my daughter who has hyperacusis. The newer Boost model seems to
be advancing further with diagnostics to help figure out the required sound
profile of the listener.

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40four
I'm not sure I understand how hearing aids work. I think they pick up sound
and amplify it for the user, giving them the ability to adjust the volume.

I remember seeing my grandmother's aids. They had a little knob on the side to
adjust the volume, and if she turned one to high they would produce an ear
piercing loud 'shriek' for eveyone in the room.

This was years ago, I'm sure the technology has progressed since then. But now
that I really think about it, how does a device like that just not accelerate
hearing loss.

We know we're not supposed to listen to earbuds/ headphones too loud, or risk
ear damage. Seems like hearing aids are a kind of earbud that amplify external
sound.

Seems like a high risk of folks blasting the volume, and damaging already poor
hearing even further. Or a least a sure path to a nice case of tinitus over
time.

What am I missing?

~~~
pjc50
I have a set of the modern-but-cheap NHS hearing aids.

The diagnostic process for getting them involves playing a set of random quiet
tones, and you press a button whenever you hear one (and not when you don't).
This produces a hearing profile showing how much hearing loss you are
experiencing _and at which frequencies_. Usually the higher ones. If the
profile is bad enough and you are given the hearing aids, the profile is
downloaded into them and used as a parametric equaliser.

The amplification is not user-controllable, so you can't set it to dangerous
levels.

There is also feedback cancellation - there may be a small shriek on power-on
(along with the cheerful bootup chime), but it detects this and mutes that
frequency.

They aren't magic, but they do make it much easier to understand speech,
especially consonants and 's' sounds with high frequency components. Also
little things like being able to hear my oven timer's high pitched beep when
not in the kitchen.

There is a latency on the amplification and filtering. The ear adapts but I
can occasionally notice it.

Battery life is about a week from non-rechargeable zinc-air batteries, £10 for
60 from Amazon or free on the NHS if you can be bothered to go to them.

~~~
mongrelion
Do you have a link to the device that you're talking about?

~~~
jrace
The Yuu is an older Unitron model:
[https://www.audiologyonline.com/releases/unitron-hearing-
int...](https://www.audiologyonline.com/releases/unitron-hearing-introduces-
yuu-4009)

Often subsidized hearing providers will be given low-cost older hearing aids
from manufactures.

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newyankee
Related point: There is a multi billion dollar market to someone who can make
a 2 part aid which is almost invisible.

Something like a smartphone handling the initial processing and then
transmitting via a small earpiece inside the ear with some innovative design
for making it discreet.

Hearing aids really are a racket for most part.

~~~
shariqm
There's plenty of hearing aid apps on iOS and Android. They haven't really
taken off because of the delay introduced by the mobile OS and the wireless
transmission (> 10ms) causing you to hear an annoying echo effect.

~~~
jrace
In my experience the delay was not the issue, adoption and use of the
technology was, both by the user and the practitioner.

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MrBuddyCasino
Ok so scanning the paper, this is just some Adafruit breakout boards (class D
amp & electret mic) cobbled together. Is there something that is novel?

~~~
Cogito
The novelty is the application, at the price point, tested against a
specification. Given that this is an invention/design, seems like a completely
respectable piece of work that is not at all redundant (which is the
implication I read in your question) even if obvious in retrospect.

> The LoCHAid costs only 98 cents (<$1) to mass manufacture and can be
> personalized for each user through a 3D-printable case.

> It is designed to be an over-the-counter (OTC) self-serviceable solution for
> elderly individuals with ARHL.

> Electroacoustic measurements show that the device meets most of the targets
> set out by the WHO Preferred Product Profile and Consumer Technology
> Association for Hearing Aids.

> Simulated gain measurements show that the LoCHAid is well fitted to a range
> of ARHL profiles for males and females between the ages of 60-79 years.

> Overall, the measurements show that the device has the potential to benefit
> individuals with ARHL. Thus, our proposed design addresses a long-standing
> and grand challenge of affordable and accessible hearing technology for
> every elderly person on this planet.

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m463
There are lots of inexpensive hearing aids available on amazon right now.

They say they are personalized, but that seems to only be for physical fit.

I suspect, but do not know for certain, that they also need to be tuned to the
individual sonically. This would be make things understandable instead of
shrill, and prevent additional hearing loss from overamplification.

Maybe the same as getting eyeglasses that don't match your prescription.

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dr_dshiv
I understand that hearing aids, as a medical device, are a bit of a racket,
costing thousands. But, some new policy is in the works that favours consumer
tech innovation. Anyone knowledgeable?

~~~
shariqm
Yeah, the OTC (over-the-counter) hearing aid act passed in 2017 [1]. It says
the FDA has to release reduced regulations for the sale of hearing aids OTC by
August 2020. There will be a bunch of new players, e.g. Bose HearPhones and
maybe even Apple (checkout Live Listen).

The challenge will be how to fit a hearing aid without an audiologists help.
This will be especially difficult for older people.

Hopefully it will bring down the price of hearing aids substantially though.

[1] [https://www.warren.senate.gov/newsroom/press-
releases/bipart...](https://www.warren.senate.gov/newsroom/press-
releases/bipartisan-over-the-counter-hearing-aid-legislation-to-become-law)

~~~
Uhrheber
That's actually not a bad idea, a lot of people already have headphones with
integrated microphones and processors.

Noise cancellation headphones could be easily transformed into hearing aids
with a change of the firmware. In fact, they could be excellent hearing aids,
because they probably have more computing power than the average professional
hearing aid.

~~~
sannee
Bose apparently already does something like this. See Bose Hear.

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bufferoverflow
So where can I buy it?

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anonytrary
What's the sampling rate? How good is the sound? How many input channels?

Sorry if these were answered in the PDF. A quick CTRL+F on the preview did not
find any of these keywords, and I'm too lazy to SciHub right now.

~~~
magicalhippo
> What's the sampling rate?

Analog solution.

> How many input channels?

The microphone amplifier is single channel, the output amplifier is stereo,
though they only use one and drive both jack outputs from the right channel.

