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I recently discovered a great app I've been using to proofread to audio called AudioStretch. It is actually aimed at musicians, but it's super easy to use for proofreading alongside the audio -- easy to pause, move forward or backwards, speed up or slow down, etc. It's $9.99 in the app store, which is a bit steep, but so worth it for the ease of proofing. I love the app so much that I actually wrote about it. It just makes the whole process so much easier.