An NSIndexSet that specifies which audio channels should be sent through the connection. The indices in the set should be between 0 and the number of volumes in QTCaptureConnectionAudioVolumesAttribute. This attribute allows applications to selectively disable certain audio channels from being sent through the connection. The value of this attribute should be an NSIndexSet that contains only the channels that should be used. By default, all audio channels are sent though a connection. This string value can be used in key paths for key-value coding, key-value observing, and bindings.

Available in Mac OS X v10.5 and later.