The 3A algorithm refers to three audio processing algorithms: Acoustic Echo Cancellation (AEC), Active Noise Control (ANC), and Automatic Gain Control (AGC).
The 3A processing is automatically enabled for the audio stream with the STREAM_USAGE_VOICE_COMMUNICATION configuration. In common recording scenarios, 3A is not enabled. It is enabled only for VoIP calls. You need to configure the corresponding StreamUsage type when playing audio streams.
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