A manipulation in which the Duration of a sound is altered. Time stretching can be used to make sounds longer or shorter.

Time-stretching can be done on its own using digital technology, or can be linked with pitch-shifting as it was with analogue technology (for example as in playing a record at the wrong speed).

[In digital music, time stretching and compression involve the elongation or reduction of a recording without changing its pitch. Whilst using tapes, the pitch rose or descended according to the amount of increased or decreased speed.]

Large-scale stretching can lead to granular textures; large-scale compression can lead to the source becoming masked.