How to use autotune on audio files in Audacity through a free plug-in

You can enable autotune in Audacity by installing the GSnap plug-in, which works with Windows, Mac, and Linux computers.

You can't speed up Audible on a Mac, but you can on a mobile device — here's how

To speed up an Audible audiobook on your Mac, you'll need to use the mobile audible app and a third-party program.