Android Emulator degrades Bluetooth audio output

To avoid this problem, disable the microphone in the emulator by adding hw.audioInput=no to the config.ini file of the Android Virtual Device (AVD). To find an AVD's config.ini file, go to the AVD in the Device Manager, click its overflow menu, and select Show on Disk.

Reference: https://developer.android.com/studio/run/emulator-troubleshooting#emulator-degrades