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
Built withArduinoTeensy3D printing
- difficulty
- ●●●●○
- time
- several weekends
- license
- MIT
- repo
- repo ACTIVE150 stars
●●●●○ · several weekends · MIT · 150 stars · repo ACTIVE
WHAT YOU’LL NEED
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COMPAREE VERDICT
Tympan is an open hearing-aid research 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; here the chain from microphone to speaker is documented, and the firmware is Arduino code you flash yourself, with examples for multi-band compression, frequency shifting and compression, noise reduction and feedback cancellation. Researchers use it 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. Most people start with an assembled board and headphones; building your own board or the behind-the-ear earpiece means fine surface-mount soldering and iteration on 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. If you just want better hearing, see an audiologist.
IN THE REPO
GOOD TO KNOW
- —Hardware files are published: main board schematics and layouts per revision, earpiece designs and enclosure models — under MIT or CERN-OHL-P depending on the revision, with the earpiece repo unlicensed.
- —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 lives in per-revision repositories (Tympan_Rev_E_Hardware, Tympan_Rev_F_Hardware, Tympan-Rev-G-Hardware) and the earpiece in Earpiece_BTE-RIC_V1.
- —The library is MIT. Hardware licences vary by revision (Rev E MIT, Rev F CERN-OHL-P-2.0), and the earpiece repository has no licence file — check the repo for the part you use.
Parts to buy
6 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
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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(Assembled Tympan boards are sold through tympan.org; otherwise pull the manufacturing files from the hardware repository for your revision (e.g. Tympan_Rev_F_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?
No — assembled Tympan boards are sold at tympan.org. If you want to fabricate your own, the per-revision hardware repositories have the design files, but expect fine-pitch surface-mount assembly.
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 cells and highly optimised low-power chips; Tympan uses a rechargeable lithium battery and a general-purpose Teensy processor, so it runs for far less time between charges. Check tympan.org for the figure for your board revision.
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
No community builds yet — be the first, we feature the best ones.
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.
CompareeTEAM2mo agoedited
Practical notes from our verification: the Tympan_Library repository holds the Arduino code and examples and is actively maintained, with commits as recent as October 2026. The hardware lives in separate repositories under the Tympan GitHub organisation, one per board revision (for example Tympan_Rev_F_Hardware and Tympan-Rev-G-Hardware), and the behind-the-ear earpiece designs are in Earpiece_BTE-RIC_V1, which includes an assembly guide and bill of materials. Licences are mixed: the library is MIT, Rev F hardware is CERN-OHL-P-2.0, and the earpiece repository has no licence file. Ready-made boards are sold through the tympan.org shop, so most people start with a finished board and headphones rather than building the hardware. Tympan has its own YouTube channel, with an overview of the platform for hearing research. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.