See Also: AudioSession Members
Both the MonoTouch.AVFoundation.AudioSession and MonoTouch.AVFoundation.AVAudioSession reference the same underlying singleton object. Properties in MonoTouch.AVFoundation.AudioSession were deprecated in iOS 7.0, and MonoTouch.AVFoundation.AVAudioSession appears to be the preferred path forward.
You use the various AudioSession methods to control how the input and output are handled by the operating system, configure the recorder and speakers, control where the audio is played to, and where the audio is recorded from. AudioSession also provides a mechanism to start and stop using the audio system and to monitor changes to the audio system.
Both the initialization sequence and the use of some properties on AudioSession can throw an MonoTouch.AudioToolbox.AudioSessionException.
Your application can use the AudioSession.AddListener(AudioSessionProperty, MonoTouch.AudioToolbox.AudioSession.PropertyListener) method with the AudioInputAvailable value to monitor when the microphone becomes available.