I am trying to research and find whether audio quality degrades if sped up and then slowed back down to it's normal speed, on the one hand its shortening the track so there is bound to be a loss of quality but I am not sure this is completely the right thinking.
1 Answer
It depends what method is used.
If it's simply played back 'faster' without actually changing the data, then of course there is no lasting damage. This would be how a simple sampler would ordinarily do it, by changing the speed, ie data rate, of the playback.
If you resample so the same amount of audio plays back in half the time at the same sample rate - then you've lost half the data.
1 second at 44.1 KHz requires 44,100 samples. Double-speeding that algorithmically to last only half a second will only need 22,050 samples. The rest is lost forever.
In practise, many modern DAWs will never actually touch the original & will always work on copies, so you can always go back to the original rather than have to resample again.