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volume

Get or set the speech volume for a synthesizer.

Declaration

static let volume: NSSpeechSynthesizer.SpeechPropertyKey

Discussion

An NSNumber that specifies the synthesizer’s speech volume.

Volumes are expressed in floating-point values ranging from 0.0 through 1.0. A value of 0.0 corresponds to silence, and a value of 1.0 corresponds to the maximum possible volume. Volume units lie on a scale that is linear with amplitude or voltage. A doubling of perceived loudness corresponds to a doubling of the volume.

This property is used with setObject(_:forProperty:) and object(forProperty:).

See Also

Speech Property Keys