Instance Property


The system wide output volume set by the user.


@property(readonly) float outputVolume;


A value in the range 0.0 to 1.0, with 0.0 representing the minimum volume and 1.0 representing the maximum volume.

The system wide output volume can be set directly only by the user; to provide volume control in your app, use the MPVolumeView class.

You can observe changes to the value of this property by using Key-value observing.

See Also

Working with Audio Device Settings


The gain applied to inputs associated with the session.


A Boolean value that indicates whether the input gain can be set.

- setInputGain:error:

Changes the input gain to the specified value.


The latency for audio input, measured in seconds.


The latency for audio output, measured in seconds.


The current audio sample rate, in hertz.


The preferred sample rate, in hertz.

- setPreferredSampleRate:error:

Sets the preferred sample rate for input and output.


The current I/O buffer duration, in seconds.


The preferred I/O buffer duration, in seconds.

- setPreferredIOBufferDuration:error:

Sets the preferred audio I/O buffer duration, in seconds.

Beta Software

This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.

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