Free, open-source hearing assistance for Android — no root, any earbuds.
Apple ships a hearing screening and a hearing-aid mode on AirPods Pro 2/3 — but locks them to iPhone/iPad/Mac. OpenHearing brings open hearing assistance to Android, working with any earbuds: screen your hearing, build a personalized amplification profile, and boost quiet speech in real time.
Complement to LibrePods: LibrePods drives AirPods' own hearing-aid mode (root required); OpenHearing does its own on-device processing — no root, any earbuds.
OpenHearing is a sound-amplification and hearing-assistance tool. It is NOT a medical device, NOT a certified hearing aid, and NOT a substitute for a professional hearing exam. It does not diagnose or treat any condition. If you have concerns about your hearing, see an audiologist or doctor. Keep the volume comfortable and stop if anything is too loud.
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| Onboarding acknowledge the disclaimer |
Home | Screening heard / not-heard, with volume cap + stop |
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| Results audiogram + prescribed gain |
Hearing assist | Settings comfort calibration, high contrast |
Screenshots are from the running app on an emulator (the screening values shown are from an automated test pass).
▶️ A real demo video is coming after on-device validation.
- 🎧 Pure-tone hearing screening — adaptive (Hughson–Westlake) staircase, per ear, per frequency → an audiogram.
- 🔊 Real-time hearing assist — multi-band gain from your audiogram, wide dynamic-range compression, and a feedback/howl guard.
- 🛡️ Safety first — a hard look-ahead output limiter (extensively tested), comfort calibration to cap loudness, and an always-available instant Stop.
- ♿ Accessibility-first — large controls, high-contrast theme, scalable text.
- 🔒 Private by design — no accounts, no analytics, no ads, no network access. Audio is processed on-device and never recorded or transmitted.
- 🎧 Any earbuds — wired or Bluetooth; AirPods support is a future enhancement.
- Install — sideload the APK from Releases (F-Droid coming).
- Read & accept the safety disclaimer on first launch.
- Run the hearing screening — put on a headset in a quiet room, tap Run hearing screening → Start. After each tone, tap Yes, I heard it or No, I didn't. The volume cap and Stop / mute are always on screen.
- Review your results — a per-ear audiogram and the prescribed amplification (half-gain rule). This is saved as your profile.
- Turn on Hearing assist — grant microphone access, set the amplification level, tap Start assist. Sound around you is amplified in real time; tap Stop assist any time.
- Calibrate comfort (Settings) — preview the maximum loudness and lower it until comfortable; that caps how loud assist mode can ever get. Toggle the high-contrast theme here too.
See docs/SAFETY.md, docs/CALIBRATION.md, and docs/DEVICE_TESTING.md for details.
Privacy is platform-enforced, not just promised: OpenHearing declares no
INTERNET permission, so it physically cannot make network calls. Your hearing
data, profile, and audio never leave the device — and microphone audio in assist
mode is processed in real time and never recorded or transmitted.
- No accounts, no ads, no analytics, no trackers, no network.
- Dependencies are AndroidX / Compose / Hilt / Kotlin only — no Google Play Services, Firebase, or ad/analytics SDKs.
Verify it yourself from the APK:
aapt dump permissions OpenHearing-<version>.apkThe only permissions are RECORD_AUDIO (the mic for assist mode),
FOREGROUND_SERVICE + FOREGROUND_SERVICE_MICROPHONE (to keep assist running with
a visible notification), and POST_NOTIFICATIONS. See docs/PRIVACY.md.
Requirements: JDK 17, Android SDK (API 35, build-tools 35.0.0). Point the build
at your SDK via local.properties (sdk.dir=...) or ANDROID_HOME.
./gradlew ktlintCheck detekt test testDebugUnitTest # lint + unit tests
./gradlew assembleDebug # debug APKCI runs the same checks on every push/PR. Release/signing steps are in docs/RELEASE.md.
Early alpha: the full software pipeline (screen → profile → real-time assist) is built and unit-tested, but not yet validated on real hardware.
| Area | Status |
|---|---|
| Audiogram screening engine (staircase, fitting) | ✅ pure-Kotlin, unit-tested |
| Real-time assist DSP (EQ + WDRC + feedback guard + limiter) | ✅ unit-tested; limiter safety suite is the release gate |
| Android audio engine + foreground assist service | ✅ builds — needs on-device validation |
| Onboarding, persistence, assist UI, accessibility | ✅ |
| Comfort calibration + output ceiling | ✅ (true dB SPL calibration needs a meter) |
| Signed release build, privacy, F-Droid metadata | ✅ — docs/RELEASE.md |
| AirPods Pro 2/3 detection / transparency routing | ❓ UNVERIFIED — docs/PROTOCOL.md |
On AirPods: the protocol is reverse-engineered, not public; we build on LibrePods/CAPod. It may not be fully controllable from Android without root/firmware access — which is why OpenHearing works fully on any earbuds first.
Clean multi-module Kotlin (Compose/Material 3, MVVM, Hilt, coroutines). DSP and safety logic live in pure-Kotlin modules so they're unit-tested with no emulator. See ARCHITECTURE.md.
:app · :core-common (units + safety constants) · :core-audiogram (screening
- fitting) ·
:core-audio(DSP + limiter) ·:airpods-protocol(UNVERIFIED) ·:data(persistence).
Contributions welcome — especially hardware testers (AirPods Pro 2/3 + an Android phone) and accessibility feedback. See CONTRIBUTING.md, CODE_OF_CONDUCT.md, and docs/SAFETY.md.
GPLv3 — see LICENSE.
- LibrePods and CAPod for the AirPods reverse-engineering groundwork.
OpenHearing is an independent project, not affiliated with or endorsed by Apple. "AirPods" is a trademark of Apple Inc., used only to describe hardware compatibility.