speakingRate property
Speaking rate/speed, in the range [0.25, 4.0].
1.0 is the normal native speed supported by the specific voice. 2.0 is twice as fast, and 0.5 is half as fast. If unset(0.0), defaults to the native 1.0 speed. Any other values < 0.25 or > 4.0 will return an error.
Optional.
Implementation
core.double? speakingRate;