Changes both the sound tempo and pitch, as if an LP disc was played at wrong RPM rate. The use of this method will speed up the sound playback and voices will result altered; if you don't want to alter voices, use the SetTempoPerc method. The current rate percentage can be obtained through the GetRatePerc method. The current effective playback rate ratio, that may be also affected by the SetTempoPerc method, can be obtained through the PlaybackRateRatioGet method.
This method doesn't work with sounds with more than 2 channels (5.1 or 7.1) or if the EnableMixingFeatures property has been set to false.
When dealing with video clips, calls to this method will have no effect if the video clip has not been loaded with the VideoPlayer.LoadForTempoChange, VideoPlayer.LoadFromMemoryForTempoChange, VideoPlayer.LoadFromMemorySyncForTempoChange or VideoPlayer.LoadSyncForTempoChange methods.
After a successful call to this method, the duration of the song will change: the new duration, expressed in seconds, is notified through the SoundDurationChanged event. The new duration can also be obtained through the SoundDurationGet and SoundDurationStringGet methods by setting the bKeepCountOfRateChange parameter to "true".
Further details about songs mixing can be found inside the How to mix your songs section.