Mp4a.40.2 -140- 90%

The string "mp4a.40.2 -140-" refers to an and a specific encoder/configuration parameter (likely from FFmpeg or a similar tool).

"mp4a.40.2 -140-" = AAC-LC audio, 22.05 kHz (likely), 140 kbps bitrate, often seen in YouTube audio format 140 or FFmpeg debug output. mp4a.40.2 -140-