Bypassing Airpods Hearing Aid Georestriction With A Faraday Cage

When Apple recently announced the hearing aid feature on their new AirPods Pro 2, it got the attention of quite a few people. Among these were [Rithwik Jayasimha] and friends, with [Rithwik] getting a pair together with his dad for use by his hard-of-hearing grandmother. That’s when he found out that this feature is effectively limited to the US and a small number of other countries due them being ‘regulated health features’, per Apple. With India not being on the approved countries list and with no interest in official approval legalities, [Rithwik] set to work to devise a way to bypass this restriction.

As noted in the blog post, the primary reason for using AirPods here instead of official hearing aids is due to the cost of the latter, which makes them a steal for anyone who is dealing with mild to moderate hearing loss. Following the official Hearing Aid feature setup instructions requires that your location is detected as being in an approved country. If it is, the Health App (on iOS 18.1) will popup a ‘Get Started’ screen. The challenge was thus to make the iOS device believe that it was actually in the FDA-blessed US and not India.

Merely spoofing the location and locale didn’t work, so the next step was to put the iOS device into a Faraday cage along with an ESP32 that broadcast California-based WiFi SSIDs. Once the thus treated iPad rebooted into the US, it could be used to enable the hearing aid feature. Next [Rithwik] and friends created a more streamlined setup and procedure to make it possible for others to replicate this feat.

As also noted in the blog post, the Hearing Aid feature is essentially a specially tuned Transparency mode preset, which is why using AirPods for this feature has been a thing for a while, but with this preset it’s much better tuned for cases of hearing loss.

Apple May Break Into The Hearing Aid Industry

When the entry of a tech giant such as Apple into a market represents its liberation from exploitation, that market must be really broken, yet the reported FDA approval of the hearing aid feature in the latest AirPod earbuds seems to represent just that. The digital hearing aid business is notorious for its sharp sales practices and eye-watering prices, so for all Apple’s own notoriety the news might actually represent a leap forward for consumers in that sector. We have to ask though, if Apple of all people are now the Good Guys, where has the world of electronics gone so badly wrong?

Your grandparents decades ago would have had a simple analogue hearing aid if they had one, usually a small transistor circuit and perhaps with some kind of analogue filtering.  Digital aids with DSP algorithms to pick out speech arrived some time in the 1990s, and from there evolved a market in which their high prices increasingly didn’t match the cost of the technology or software involved. At least in the UK, they were sold aggressively to older people as less cumbersome or better than the National Health Service aids, and if you had an older person in the family it was routine to see pages and pages of targeted junk mail offering dubious financial schemes to pay for them.

The question then, given that a modern hearing aid has a relatively cheap microcontroller and DSP at its heart, why has the open source community not risen to the challenge? The answer is that they have, though the Tympan seems an over-expensive trinket for what it is and the LoCHAid and Open Speech Platform seem to have sunk without trace. Can we do better?

Header: Gregory Varnum, CC BY-SA 4.0 .

Open Source Ear Monitoring Platform Listens To Your Ears

All sorts of exciting things happen in your ears, and now there is a good open source way to monitor them. Open Earable is a new project from a group of researchers and companies that monitors and records what is going on in your ear.

The project is designed as an easy-to-build, cheap way for audiologists and others to capture data about what is happening inside and around the ear. It’s a clip-on device that looks like a small hearing aid but has a six-degree Inertial Measurement Unit (IMU) and several other sensors to measure things around your ear and inside the ear canal. A pressure and temperature sensor measures the air pressure and temperature just inside the ear canal, and a small speaker can squirt sound right in there.

A button on the outside allows the user to control the device, and it can play back or record sound to the internal SD card memory. These are all controlled by an Arduino that includes Bluetooth Low Energy. The existing design only allows you to play a stored WAV file, not streaming audio. That’s a solvable problem, though, so it could also be turned into a set of hacker headphones.

Joking aside, this looks like an exciting research project and a useful tool for researchers. The GitHub repository for version 1.3 of the project lays it all out, including a full BoM and code, and the STL files for the case and PCB designs are in the Resources section of the site.

[Updated 18/10/2023 to correct IMU to Measurement, not Management. Intertial management needs a different set of devices]

It Costs WHAT?! A Sounding Into Hearing Aids

We are accustomed to medical devices being expensive, but sometimes the costs seem to far exceed reasonable expectations. At its most simplistic, a hearing aid should just be a battery, microphone, amplifier, and speaker, all wrapped in an enclosure, right? These kinds of parts can be had for a few dimes, so why do modern hearing aids cost thousands of dollars, and why can’t they seem to go down in price?

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Hearing Aid Reads Your Mind

If you’ve ever seen an experienced radio operator pull a signal out of the noise, or talked to someone in a crowded noisy restaurant, you know the human brain is excellent at focusing on a particular sound. This is sometimes called the cocktail party effect and if you wear a hearing aid, this doesn’t work as well because the device amplifies everything the same. A German company, Fraunhofer, aims to change that. They’ve demonstrated a hearing aid that uses EEG sensors to determine what you are trying to hear. Then it uses that information to configure beamforming microphone arrays to focus in on the sound you want to hear.

In addition to electronically focusing sound, the device stimulates your brain using transcranial electrostimulation. A low-level electrical signal tied to the audio input directly stimulates the auditory cortex of your brain and reportedly improves intelligibility.

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Wire Loop And Amplifier Solve Audio Problem For The Hearing Impaired

Imagine being asked to provide sound reinforcement for a meeting that occurs in a large room, where anyone can be the speaker, and in a situation where microphones would hinder the flow of the meeting. Throw in a couple of attendees who have hearing disabilities, and you’ve got quite a challenge to make sure everyone gets heard.

Such a situation faced [David Schneider] at his Quaker meetinghouse, which he ended up solving with this home-brew audio induction loop system. The worship style of conservative sects of the Religious Society of Friends, as the Quakers are formally known, is “silent worship”, where congregants sit together in silence until someone feels moved to share something. Anyone can speak at any time from anywhere in the room, leading to the audio problem.

Rooms mics and a low power FM transmitter didn’t work because those using radio as aids to hearing the service felt awkward, so [David] decided to take advantage of a feature in the hearing aids worn by some members: telecoils. These are inductive receivers built into some hearing aids to send sound directly to them using magnetic fields generated by a loop in the listening area. [David]’s loop ended up being 240 meters of 20-gauge copper wire in the attic above the meeting room. The impedance ended up close to 8 ohms, perfect for feeding directly from the speaker terminals of an old stereo amplifier. Pumping 160 Watts into the coil allows the hearing-aid wearers below hear the service now.

There’s still work to be done on the input side to improve audio quality, but [David]’s solution is elegant in that it helps those who need it most using technology they already have. And perhaps those who need but don’t yet have hearing aids can roll their own.

Meet Tympan, The Open Hardware Hearing Aid

If you’re the kind of person who’s serious about using open source software and hardware, relying on a medical device like a pacemaker or an insulin pump can be a particular insult. You wouldn’t trust the technology with your email, and yet you’re forced to put your life into the hands of a device you can’t examine yourself. Unfortunately we don’t (yet) have any news to report on open source pacemakers, but at least now there’s an open software and hardware hearing aid for those who need it.

The Tympan project aims to develop a fully open source hearing aid that you can not only build yourself, but expand and modify to fit your exact specifications. Ever wanted to write code for your hearing aid with the Arduino IDE? No problem. You want Bluetooth, I2C, and SPI? You got it. In truth we’re not sure what this kind of technology makes possible just yet, but the point is that now those who want to hack their hearing aids have a choice in the matter. We have no doubt the community will come up with incredible applications that we can’t even begin to imagine.

But these open hearing aids aren’t just hackable, they’re affordable. Traditional hearing aids can cost thousands of dollars, but you can buy the Tympan right now for $250. You don’t even need to check with your health insurance first. Such a huge reduction in price means there’s a market for these outside the hardware hacking crowd, and yet another example of how open source can put cutting edge technology into the hands of those who would otherwise have to go without.

The latest version of the Tympan hardware, revision D, is powered by the Teensy 3.6 and features a Sierra Wireless BC127 Bluetooth radio, dual MEMS microphones, and even a microSD slot for recording audio or logging data. It might be a bit bigger than the traditional hearing aids you’re used to seeing, but with an external microphone and headphone setup, the wearer could simply keep it in their pocket.

We’ve seen DIY hearing aids before, but unless you’re willing to carry a breadboard around with you, they’ve generally been limited to proof of concept sort of builds. We’re glad to see a mature project like Tympan join the growing movement for open source medical hardware; it’s a another big step forward towards democratizing these critical pieces of technology.