The Android emulator routes audio played on the runner host through to the emulator’s microphone input. Use device.passAudioAsMicrophoneInput(...) to play an audio file during a flow, and your app will receive it as microphone input.
Microphone injection and audio capture work on emulators only, not on real Android phones.
Start your app recording before you call this. passAudioAsMicrophoneInput plays the file and resolves only once playback has finished, so awaiting it first plays the whole file into a microphone nobody is listening to, and the recording that follows captures silence. delaySeconds does not work around this either, since it is awaited inline as well.
Store your audio file in team storage and reference it via process.env.TEAM_STORAGE_DIR. See Use files in flows for instructions. Examples
Inject audio into the microphone
Start the recording in your app, then play the audio into it:
Start playback before your app begins listening
If your app needs audio already flowing when it starts listening, hold the promise and await it once the app is ready:
Pull a recording off the emulator
When to use
- Your app records audio or processes microphone input and you need to test that flow with known audio data.
- Your app has voice commands or speech recognition features.
- Your app validates or analyzes microphone input.
- Your test needs to run the same audio scenario repeatedly with consistent inputs.
Options
passAudioAsMicrophoneInput accepts delaySeconds (wait before playback starts) and durationSeconds (cap playback length; omit to play the whole file). See the Android Device Controls for the full signature.
delaySeconds delays playback, but the call still resolves only once playback has finished. Use it to line playback up with something your app does after it starts listening, not to start the recording after the call.
Verifying the injected audio
Assert on something your app derived from the audio, such as the text a speech-recognition field transcribed. A file appearing on disk only proves your app recorded something, and a recording made in the wrong order contains silence while still producing a file.
device.captureAudioOutput cannot confirm that injection reached your app. The capture is taken on the runner host, where the injected audio is present whether or not the emulator ever passed it to the guest, so it returns your audio even when your app heard nothing. The same is true of any other host-side check. Verify from inside the app instead.
Full sample test
