From JS8 Media:
AudioSpeed allows you to alter the playback speed of audio (and video) files, and independently or in addition alter the pitch rate. Ideal for learning tricky passages of music or vocals, as it will adjust the playback speed without altering the pitch, if you don't adjust the pitch slider. AudioSpeed has a large range of features, allowing you to adjust the playback speed and pitch exactly as you want, and to specify a loop section to repeatedly hear the adjusted audio. Key features include:
- Drag and drop table for adding audio and video files.
- Speed slider for adjusting the playback speed from a range of 2.5 down to 0.35. Also allows you to play audio in reverse from speeds of -0.35 to -2.5
- Pitch slider for adjusting the playback pitch rate.
- Loop buttons for setting the loop start and end points, useful for repeatedly playing a section of audio at a different speed.
- Full audio quality controls.
- Unobtrusive step buttons for incrementally adjusting the audio speed and/or pitch rate.
- Separate level indicator and audio info panels.
- Keyboard shortcuts for adjusting the speed, altering the pitch by semitones, and skipping forward or back.
- High quality interface for ease of use.