[gltchkrft]

Yes, but for most codecs, bitrate is variable. For the parts where the higher frequencies are present the codec is free to bump up the bitrate and it can also scale it down for silent parts or parts with low frequencies only.

[lolpython]

Sure, if it were encoded at a variable rate. But then it wouldn’t be 320kbps CBR. Normally when I see people refer to 320kbps audio they literally mean constant bitrate. If it’s variable then for LAME mp3 people would specify V0 or V2. At least that’s the taxonomy that I absorbed when I was active on what.cd

Edit: you have edited your comment to remove mention of 320kbps so my comment is now moot :)

[gltchkrft]

Yes, but afaik Spotify uses Ogg Vorbis, which is inherently VBR. https://en.wikipedia.org/wiki/Vorbis

[gltchkrft]

Sorry. I removed the part about 320 kbps being an average, since I realized it was wrong, but you were faster :D.