I'd like to remove a laugh track from a sitcom

Audacity Help Forum Windows
1

Firstly, I’m very much a newb.

Secondly, if you read my title and scoffed, it’s not quite as dumb as it sounds. I think. The show is How I Met Your Mother and the audio is in 5.1. It seems like the audio is distributed thus:
Front left and right: dialogue, laugh track, music.
Front centre: dialogue.
Rear left and right: music.

Is there a straightforward way to remove only the audio from the front left and right channels which is unique to them, ie. the laughter? I tried looking it up and found stuff about the Invert and Vocal Reduction effects, and tried having a play with them, but I really don’t know what I’m doing. Obviously I could watch the show with two of the channels muted, but I’d prefer a more elegant solution if such a thing is possible.

2

Assuming that is correct:

  1. Import the file (“File menu > Import > Audio”)
    The file should import as 6 audio channels.

  2. Identify which are the front left / right channels with the laugh track, and delete those tracks by clicking on the [X] in the top left corner of the track.

  3. You should now be left with 4 mono audio tracks. Identify the Rear left and right channels and join them to create a stereo track (see: https://manual.audacityteam.org/man/splitting_and_joining_stereo_tracks.html)

  4. Open the Mixer Board (View menu) and adjust the levels so that the balance between tracks gives the best sounding mix. Take care not to make any of the tracks too loud or it will sound distorted.

  5. When you are happy with the mix, select all tracks (“Ctrl + A”), then select “Tracks menu > Mix > Mix and Render”)

  6. You should now have one stereo track. Ensure that this track is selected, and Normalize to -1 dB (See: https://manual.audacityteam.org/man/normalize.html)

  7. Export as a WAV file (or some other audio format). “File menu > Export > Export as WAV”.

3

Thanks for the reply, but is there any way to execute a sort of ‘diff’ command to just separate out what the two front channels don’t share with any other channels? Like some sort of reverse-joint-stereo thing, so dialogue (and possibly other audio) is left intact in those channels.

4

For a stereo track, you can execute a ‘diff’ command, by inverting one channel and then mixing the two channels. I don’t know of any way to transpose that to a multi-track recording in a meaningful way. I don’t think that any simple “algebraic” operation will give meaningful results.