isolate human voice in audio

[agilpwc]

I would like to know what filters to use in AviSynth to apply to a sound track to isolate the human voice? In other words get rid of or diminish all other sounds besides humans talking.

In my particular case I want to diminish the sounds of dogs barking in the background.

Does anyone know what frequencies human vocals are typically at?

Kind of the reverse of a kaoroke maker, but instead of getting rid of human vocals, leaving only the music, I want to get rid of everything else, leaving the human vocals.

Thanks

[slk001]

I don't know of any filters that will do this in AVISynth. You would probably be better off using an audio editing program, like Audition for this.

The way that I do this is to first remove the voice as much as possible from a copy of the original. On music tracks, the music may be stereo, but the voice is still basically monoral. Inverting one track, then adding it to the other, should mostly remove the voice. Now using the resulting track, add it back to one of the original channels (experimenting with inverting, etc) to reduce the background noise. You can then do the same thing to the other channel.

The results won't be perfect, but they might just be acceptable to you. I've had some luck doing this.

[ChiDragon]

http://en.wikipedia.org/wiki/Voice_frequency

I imagine dog "voices" would be in the same range though...

[IanB]

If the source is stereo have a go at virtualdub's advanced filtering "centre cut". It uses phase analysis, so if the persons voice is centred and the dog is ambient you might get good results. It works incredibly well with karoke.

[tebasuna51]

You can use SoxFilter (http://forum.doom9.org/showthread.php?p=761154#post761154) to filter the audio inside AviSynth.