AVAudioSession.PolarPattern
Constants that describe the possible polar patterns of the data source on an iOS device.
Declaration
struct PolarPatternOverview
The direction of a polar pattern is relative to the orientation of the data source. For example, you can use the cardioid pattern with a back-facing data source to more clearly record sound from behind the device, or with a front-facing data source to more clearly record sound from in front of the device (such as the user’s voice).