Disclaimer: I do not own anything in this video except writing the text.
Link to original background image: http://www.zerochan.net/1357385
Ignore low video bitrate, you are here for the audio.
Exported audio at AAC 48000hz 320kbps.
Apparently Youtube will encode the audio bitrate to a maximum of 192kbps, that is when you select 720p-1080p. It'll be 128kbps for 320p-480p and 60kbps for 240p.
EDIT: So apparently I found out YouTube downscales the audio to 127kbps in the end.