This is a no brainer. How do you create rubber band audio on your Mac? With a rubber band audio processor. Conveniently, the app that does that is called Rubber Band Audio Processor.
To avoid repetitive stress injury, let’s call it RBAP. What it does is change the tempo and pitch of an audio file. Drag a file onto RBAP and use the dials to change speed and/or pitch. Or, use the more precise numerical input, or one of six presets for vocal crispness.
RBAP isn’t a pretty app. It looks more like a leftover from Mac apps circa 1992. It works easily enough, though I found the dials to be cumbersome to move. The audio saved in WAV format and I couldn’t find options for other auto file formats.
It’s not much, but it’s different and easy to change pitch or speed. It would be nice if RBAP had a more 21st century look and more audio saving options, but the price won’t break your app piggy bank.