Audio Session Category Route Overrides
Specifies whether the default audio route for the PlayAndRecord category should be overridden.
Overview
The kAudioSessionCategory_PlayAndRecord category supports simultaneous input and output. You could use this category, for example, to add an effect to audio coming into the device’s microphone. By default, output audio for this category goes to the receiver—the speaker you hold to your ear when on a phone call. The kAudioSessionOverrideAudioRoute_Speaker constant lets you direct the output audio to the speaker situated at the bottom of the phone.