[BUG] Audio switches automatically and breaks the audio analysis

[rolandschuetz]

Environment

• expo-audio-studio version: 2.18.1
• Expo SDK version: 53
• Platform & OS version: iOS 18
• Device: iPhone 16

Description

Unintended switching of audio devices, Steps to reproduce:

1. Configure RecordingConfig with ios.audioSession.categoryOptions = ['AllowBluetooth'] and define a deviceId for the built-in mic
2. Start the recording, then connect bluetooth AirPods
3. The waveform stops, no new audio analysis data and the recording switches to the AirPods

Cross-Platform Validation

The above steps can be reproduced with the AudioPlayer app on iOS. I couldn't test on Android because there the recording never started.

Can this issue be reproduced in the AudioPlayground app?

• Yes, on all platforms (Web, iOS, Android)
• Yes, but only on specific platforms (please specify): iOS
• No, it only happens in my app

Reproduction steps in the AudioPlayground app (including any settings you modified):

1. Microphone: Bulit-In
2. Advanced Settings > Custom iOS Audio Settings > Mode: Measurement
3. Advanced Settings > Custom iOS Audio Settings > Category: [Allow Bluetooth]

Even if I disable Allow Bluetooth and start with the internal mic in the sample app and then connect Bluetooth, the waveform stops updating (and I guess the audio switched).

Is the behavior consistent across platforms?

• Yes, the issue occurs the same way on all platforms I tested
• No, the behavior differs between platforms (please describe the differences)

Couldn't get the app running on Android.

Configuration

{
            sampleRate: 16000,
            channels: 1,
            encoding: 'pcm_16bit',
            keepAwake: true,
            showNotification: true,
            showWaveformInNotification: false,
            autoResumeAfterInterruption: true,
            android: {
                audioFocusStrategy: 'background',
            },
            ios: {
                audioSession: {
                    category: 'PlayAndRecord',
                    // Use 'Measurement' to minimize system processing during capture for higher STT accuracy.
                    // Avoid 'SpokenAudio' which is intended for playback of spoken content.
                    // Do not set 'DefaultToSpeaker' by default to prevent forcing speaker routing while recording.
                    mode: 'Measurement',
                    categoryOptions: ['AllowBluetooth'],
                },
            },
            output: {
                primary: { enabled: true, format: 'wav' },
                compressed: {
                    enabled: true,
                    format: 'aac',
                    bitrate: compressedBitrate,
                },
            },
            // Ensure that recording continues on the default device if the current device disconnects
            deviceDisconnectionBehavior: 'fallback',

            // Animate metering at ~25 FPS
            enableProcessing: true,
            intervalAnalysis: 20,
            segmentDurationMs: 20,

            onAudioStream: onAudioStream,
            onAudioAnalysis: extractMeteringVisualizationDataFromAudioAnalysis,
            onRecordingInterrupted: handleRecordingInterrupted,
        };

Logs

no logs

Expected Behavior

No device switching

Actual Behavior

Switching to bluetooth

Additional Context

Checklist

• I have updated to the latest version of expo-audio-studio
• I have checked the documentation
• I have tested in the official AudioPlayground app
• I have verified microphone permissions are properly set up
• I have filled out all required fields in this template

[deeeed]

Hi, could you please try again with latest version? It should be much more efficient to handle long audio.