[mythtv-users] Removing laugh tracks from recordings

Brian Wood beww at beww.org
Fri May 5 00:01:52 EDT 2006

On May 4, 2006, at 9:28 PM, Jeff Simpson wrote:

>> Just curious, has anyone thought about ways to remove the Laugh  
>> Tracks
>> from Sitcoms and such?
>> Commercials can be flagged, but how about laugh tracks? It is so
>> stupid to laugh at silly stuff when they "ask" us to...
> Audio & video at any particular time is either commercial or
> not-commercial, so once you flag what a commercial is, you can easily
> remove it. Laugh "tracks" as they are called are not really tracks in
> the finished product. While they are in the studio, they have separate
> tracks for each sound source so they can adjust levels and the like,
> but once it hits your TV you only have a left track and a right track
> (or maybe 5.1 or similar, but none of those 5 are the "laugh" channel.
> But I agree with you on wanting to remove the laugh track. Some of the
> funniest things on TV and in real life are funny because nobody is
> laughing. Watch The Office (BBC or NBC), and you'll see. It's an
> office workplace sitcom without a laugh track. The fact that you just
> have to sit there in silence after an awkward moment makes it
> hysterical. But we americans aren't all ready for that advance british
> humor :-P

Yeah, a lot of Americans think that British humor is Benny Hill, and  
even Monty Python, while an interesting niche genre, is not really  

>> There is equipment available that purports to remove vocal tracks
>> from music, for "Karaoke applications. I have no idea how well it  
>> works.
> These "Karaoke applications" operate by removing all the frequencies
> around where human voice is, with a notch filter or similar. It makes
> the music sound like crap, and typically you can still hear some of it
> in the background. Because you are running a frequency filter on the
> sound, you also end up with a lot of artifacts and high-pitched noises
> (cracks, snaps, other weird stuff).  Also, because you are doing it
> digitally, you only have a limited bandwidth to begin with, so any
> further filtering and reencoding is only making it worse.
> Real karaoke machines / places / DJs have special recordings of music
> that just don't have the vocals recorded at all, so that's why they
> work. They aren't removing the lyrics, they just have a recording of
> the song that only includes the backup music (and why karaoke discs
> will say "Song Title, as made popular by Artist Name", since they
> can't really put the artists name on a disc that they don't sing on.)

Actually a lot of modern pop music would sound best with the rage of  
20 Hz. to about 20KHz. removed. Also, a lot of the recordings that  
artists do get credit for do not contain them actually performing.

>> Theoretically an application of the same technology might at least
>> reduce the level of the offending laugh track, it would be harder
>> because the content is similar to dialog which you would want to  
>> keep.
> Yup, exactly. You can identify the frequencies of laughter (which is
> quite different from person to person, and in a laugh track they have
> a lot of people, so it's probably quite a frequency spread). If you
> could remove the laugh tracks, you would probably also end up removing
> actual laughter that is supposed to be there. And probably a lot of
> actual speach, too, since I don't believe laughter is all that
> different in spectrum from speech.
>> Probably beyond anything we can economically do right now, but as you
>> say today's impossibility might be tomorrow's Blue Light Special  
>> at K-
>> Mart.
> I'd like it if they recorded everything with more tracks. Not just the
> directional-tracks like they do now, but individual mic tracks, so we
> could do our own mixing in movies and music. It'd be nice to have just
> the vocals in a song or remove the background noise on a movie. I
> guess that is probably too much for the average home media user. We
> already have the ability to select alternate audio tracks and camera
> angles....but apart from listening to a movie in spanish or the audio
> commentary track, is it ever used?

My experience with audio recording goes back to the analog days with  
recorders that said Scully on them, amazing what you could do with  
only 16 or 32 tracks.

But you're right, the average home user hasn't figured out what the  
SAP channels are, a lot of folks think it means "Spanish Audio  
Program" :-)

Bu I sure would like ot get rid of laugh tracks any way that I could,  
they are kind of like steak sauce: A good program doesn't need them  
and a bad program will not be helped by them.

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