Lip movement threshold

[susan]

I'm using the loadSpeech command with the old Avatar.Person type avatar. It seems that some minor background noise in my wav file is setting off the lip flap when there is no speech and is preventing the mouth from completely closing while the file is playing. I thought there was a way to set the threshold level so that it'll take more to activate the lips but I can't seem to figure out how to do this. I know loadSpeech takes a value (e.g. Bob.loadSpeech('talk.wav', .05)), but from what I can tell this seems only to be controling the amount that the lips open. Thanks.