I believe Tom Schumacher has done a lot of work in this area. Chris Chafe at CCRMA has worked with Tom on this stuff, I think, and he would be a good source of information, I think. Greg -- Gregory J. Sandell (sandell@epunix.sussex.ac.uk) Experimental Psychology, University of Sussex Brighton BN1 9QG England +44-273-678058 (FAX:+44-0273-678611) http://ep56c.ep.susx.ac.uk/Greg.Sandell.html