A way to automatically amplify quiet sections?

I’m working with audio on some very old VHS tapes. Occasionally the VCR loses sync with the nicam stereo track and switches to the mono track. Ihave occasional success recording again and replaying the tape from a different place, adjusting the tracking or using a different player, but sometimes I can’t get the at the original stereo signal

When the stereo is lost there is sometimes a noticeable lowering of the perceived volume of the audio:

It’s less jarring to the listening ears if I manually amplify this section to bring it in line with the surrounding, but there are sections where the dropout happens many many times (highlighted yellow):

Highlighting them manually is a bit wearisome; is ther anything in Audacity where I can get Audacity to selection highlight to sections of audio longer than X and quieter than Y? Or apply an automatic amplification of sections of audio quieter than some threshold? (Or another/better way to tackle this?)

Thanks in advance

Perhaps Limiter with make-up gain, (possibly applied repeatedly), but that could noticeably damage the good audio.

or AutoDuck a duplicate of the track with the original,
that could raise the volume of the quiet (dropout) sections but leave the good audio untouched.

[IMO Steve’s Dynamic Mirror plugin is easier to use than Audacity’s native AudoDuck].

If the dropouts are true mono perhaps that change (from stereo) could be used to selectively amplify them :thinking:

You may find, as I did, that switching off the stereo track is a good way forward. You quickly get used to the mono track and settle in to enjoy the show. Machines worked that way for years before “VHS HiFi.”

I don’t think you’re ever going to rescue a presentation with that much damage. Do machines still allow managing tracks like that?


I’ve a Panasonic F77, and a Mitsubishi HS-M58 / M68 pair that allow a good level of control of such stuff, recording levels… I’ve gone through a total of 6 different machines looking for ones that will play these 25+ year old tapes well (and they haven’t been stored kindly either - they’ve got mold, they occasionally stick together and break… the lot)

Seems repeated playing actually helps, possibly the heads are progressively tickling crap off the surface…

Thanks for the pointers Trebor, I’ll have a mess around and see what helps! :smiley: