Praat (Boersma & Weenik, 2018) is one of the best computer programs for acoustic-phonetic analysis and manipulation of sound stimuli (and it’s free!). In addition to a GUI, you can write custom code.
Here are a few useful Praat scripts I’ve written / adapted from others. For a full list, see my Github: https://github.com/michellecohn/praat-scripts/
Loading / saving into Praat
Adjusting acoustic properties
Speed up or slow down a soundfile + textgrid
At each “sp”, label separate sentence interval (e.g., from FAVE align output)
Get sentence from labeled word intervals (assumes you have (unlabeled) sentences in separate intervals)