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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| Home | Hearing check heard / not-heard, with volume cap + stop |
Results per-ear chart + suggested amplification |
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| Manual entry type in results from a professional test |
Hearing assist live volume, presets, saved profiles |
Settings comfort calibration, media EQ, high contrast |
Screenshots are from the running app on an emulator (the check values shown are from an automated test pass).
▶️ A real demo video is coming after on-device validation.
- 🎧 Pure-tone hearing check — adaptive (Hughson–Westlake) staircase, per ear, per frequency, shown as a per-ear chart — or enter results from a professional hearing test manually.
- 🔊 Real-time hearing assist, per ear — each ear gets its own fitted gain curve (stereo), with wide dynamic-range compression, a feedback/howl guard, and live volume control while it runs.
- 🎚️ Environment presets — standard / conversation / outdoors, plus multiple saved profiles you can switch between, and a quick-settings tile for one-tap on/off.
- 🎵 Experimental media EQ — apply your sound profile to music and videos from other apps (device support varies).
- 🛡️ Safety first — a hard look-ahead output limiter (extensively tested), comfort calibration to cap loudness, an always-available instant Stop, and automatic stop if your headphones disconnect.
- ♿ 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 — grab the APK from Releases (or add this repo to Obtainium for auto-updates; F-Droid submission in progress).
- Read & accept the safety disclaimer on first launch.
- Take the hearing check — put on a headset in a quiet room, tap Hearing check → Start. After each tone, tap Yes, I heard it or No, I didn't. The volume cap and Stop / mute are always on screen. Already have results from a professional test? Use Enter results manually instead.
- Review your results — a per-ear chart plus the suggested amplification (half-gain rule). Each check is saved as a dated profile, so you can keep a history and switch between profiles.
- Turn on Hearing assist — grant microphone access, pick an environment preset, tap Start assist. Sound around you is amplified per ear in real time; adjust the volume live, and tap Stop assist any time (or use the quick-settings tile).
- Calibrate comfort (Settings) — preview the maximum loudness and lower it until comfortable; that caps how loud assist mode can ever get. The optional media EQ (experimental) and high-contrast theme live 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), POST_NOTIFICATIONS, and MODIFY_AUDIO_SETTINGS (required
by Android for the optional media EQ effect). 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.