AN OPEN-SOURCE HEARING AID YOU BUILD YOURSELF AND PROGRAM IN YOUR OWN EAR
A hearing aid where you can open the case, read the code that processes sound in your ear, and change it.
by Tympan team
HealthOpen-hardware
- difficulty
- ●●●●○
- time
- several weekends
- license
- MIT
- repo
- repo ACTIVE150 stars
●●●●○ · several weekends · MIT · 150 stars · repo ACTIVE
WHAT YOU’LL NEED
- 3D printer + filament — printable parts — files are in the repo
- Electronic parts — full list with part numbers in the repo BOM
- Dev board / microcontroller — runs the project firmware
Partner
COMPAREE VERDICT
Tympan is the only fully open hearing aid platform where the sound processing running in your ear is code you can read, modify, and understand. Commercial hearing aids lock their algorithms inside sealed devices costing thousands; here the entire chain from microphone to speaker is documented, and the firmware is Arduino code you flash yourself. It is used by researchers and audiologists to test new hearing algorithms on real people in real rooms, which makes it powerful for prototyping but also means it is not a consumer product. You will hand-solder surface-mount components, debug audio signal paths, and probably iterate on the earpiece fit. The most likely mistake is treating this as a DIY replacement for a professionally fitted hearing aid — it is not. It is a workbench for people who want to experiment with hearing assistance algorithms, and if that describes you, nothing else comes close. If you just want better hearing, see an audiologist.
IN THE REPO
NOT IN THE REPO
- —Hardware files published: main board schematics, flexible PCB earpiece designs, and 3D printed case models are all available under MIT licence.
- —Arduino library is comprehensive with example algorithms for hearing assistance — compression, frequency shifting, noise reduction.
- —Assembly guides exist but assume soldering experience and basic audio electronics knowledge. Not a beginner project.
- —This is a research and prototyping platform. It is not a medical device and cannot replace a fitted hearing aid.
- —The repo is the library; hardware files live at github.com/Tympan/Hardware and github.com/Tympan/Earpiece_BTE-RIC_V1.
- —Licence is MIT for all components, including commercial use.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterHeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the documentation at tympan.org to understand what this platform is and is not(The project explicitly states it is not a medical device. Start there.)
- 2.Clone the Tympan_Library repository and browse the examples (The Arduino examples are the fastest way to see what the firmware can do.)
- 3.Decide whether to buy a pre-made Tympan board or fabricate your own(Crescent Engineering sold assembled boards; check if they still do. Otherwise pull Gerbers from github.com/Tympan/Hardware.)
- 4.Order a Teensy 4.1 or 3.6 and the audio codec IC listed in the BOM(The Teensy is the brain; do not substitute it.)
- 5.Assemble the board, flash the test firmware, and verify audio input and output with headphones before attempting the earpiece(The earpiece is the hard part. Get the main board working first.)
KNOWN ISSUES
- Treating this as a consumer hearing aid — it is a research platform. If you need hearing assistance, see an audiologist first.
- Underestimating the soldering difficulty. The flexible PCB earpiece requires fine-pitch SMD work and is not forgiving.
- Skipping the audio safety limits in firmware. You can damage your hearing with a loud transient. Always gate and limit output.
- Expecting plug-and-play earpiece fit. The behind-the-ear design requires iteration and likely custom tips for your ear canal.
- Not reading the repo structure. The library, hardware files, and earpiece designs are in separate repositories under the Tympan organization.
- Buying the wrong Teensy. Firmware is written for Teensy 3.6 or 4.1 specifically; other boards will not work without porting.
Can I use this instead of a hearing aid from an audiologist?
No. This is a research and prototyping platform, not a medical device. A professionally fitted hearing aid is tuned to your specific hearing loss by someone with diagnostic equipment. Tympan is for experimenting with hearing algorithms, not replacing clinical care.
Do I need to fabricate the PCBs myself?
You can, but Crescent Engineering has sold pre-assembled Tympan boards in the past. Check tympan.org for current availability. If you fabricate yourself, expect PCB costs of $30–60 and a weekend of SMD soldering.
What is the hardest part of the build?
The behind-the-ear flexible PCB earpiece. It requires fine-pitch soldering, careful wire routing, and iteration to fit your ear. Many builders use the main board with regular headphones first.
How does the battery life compare to a commercial hearing aid?
Shorter. Commercial hearing aids use tiny zinc-air cells and highly optimised low-power DSP chips. Tympan uses a rechargeable lithium cell and a Teensy, which is a general-purpose ARM microcontroller. Expect several hours, not several days.
Can I modify the algorithms without knowing DSP?
You can follow the examples and tweak parameters, but writing new algorithms requires digital signal processing knowledge. The library provides building blocks like compressors and filters; combining them effectively takes experience.
Community builds
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Discussion1
FROM THE COMPAREE TEAM
Researchers and audiologists use Tympan to test hearing algorithms on real people in real rooms, not just in a lab. If you built one, what would you try first — better noise suppression, frequency shifting for high-frequency loss, or something else entirely?
Tympan team
Tympan was created by researchers and engineers who wanted an open platform for hearing assistance algorithm development. Commercial hearing aids are sealed systems where only the manufacturer can adjust the processing, which limits research and personal experimentation. The project has been actively maintained since its start and is used by academic labs, audiologists, and hobbyists worldwide.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM14d ago
Practical notes from our verification: The Tympan_Library repo holds the Arduino code and examples, but the hardware schematics and earpiece designs live in separate repositories under the Tympan GitHub organization (github.com/Tympan/Hardware and github.com/Tympan/Earpiece_BTE-RIC_V1). There is no official YouTube channel — the good walkthroughs are community-made. The project is actively maintained as of August 2026 and has a small but committed user base in the research and audiology communities. The biggest barrier is not the code, it is the earpiece assembly: soldering the flexible PCB and fitting it comfortably takes real iteration, and most builders start with the main board and headphones before attempting it.