SoundTouch is a port of the SoundTouch sound processing library. The library allows real-time processing of audio in Flash 10. It includes filters that perform time compression/expansion and rate transposition. In tandem, these filters can perform pitch-shifting.

The original C++ library includes several features that have not yet been implemented in the port, including a FIR filter, which can be used to prevent aliasing during rate transposition.

Sample

var source:Sound = …;
var output:Sound = new Sound();

var soundTouch:SoundTouch = new SoundTouch();
soundTouch.pitchSemitones = -6;

var filter:SimpleFilter = new SimpleFilter(sound, soundTouch);
output.addEventListener(SampleDataEvent.SAMPLE_DATA, filter.handleSampleData);

output.play();