The reason I'm excited about this: I read quite slowly. But there's plenty of software available for speeding up audio, so I get a lot more read by listening at around 3x.
On Android, I'd recommend SmartAudioBook Player or Pocket Casts. - I just bought "How to actually Change your mind" and downloaded it via Pocket Casts.
The Audible app (for audio books) also has a useful feature for speeding things up.
If you're on a computer, you could just use the VLC player, it has these features as well. In that case I'd recommend defining hotkeys, for going faster or slower. Makes it easier to adapt the speed to the individual recording.
I second SmartAudioBook player. It has great controls for skipping and rewinding at intervals and a great shake to wake feature.
The audio version of the mega-sequence "How to Actually Change Your Mind" is now available. It's the biggest sequence we've done yet, coming in at over 8 hours of audio. Here at Castify we think this sequence is the most important one we've done so far.
On the wiki it says, "The most important technique that Less Wrong can offer you is 'How to Actually Change Your Mind'". I couldn't agree more. If you haven't read it already I'd strongly recommend it. If you have more free "ear time" than "eye time" or you learn better from listening this audio version is for you.
Feedback is welcome: support@castify.co