I have opened an .mp3 file and discovered a (visual) effect I never saw before. At some point, the waveform shifts a bit “down” from its center, and then some time later goes back to “normal”. This happens several times in this file. When listening to the file, I do not hear any distortion or the like. The file is a registration which later was aired by a radio station.
I am using Audacity 3.6.4 on macOS 12.7.6 (Monterey).
Any ideas what was happening here?
DC offset … DC offset - Audacity Manual
Thank you, Trebor, for the link to the manual.
But: shouldn’t the DC offset be “constant”? It seems always to be only a few seconds, always less than one minute, and it appears several times in the file. Did the author switch on and off a defective device? Mh…
It can change gradually … “slowly changing DC bias”.
IIRC @Steve did make a plugin to correct slowly changing DC offset, but I don’t know if it could cope with rapid changes like 32:05 …
If it’s just the one instance it could be fixed manually.
