Goldwave is an excellent program for Windows for processing/displaying sound files. It is shareware.
Jeremy Ward says: I used a microsoft free SST for my senior design project. I liked it's simplicity and features. I thought some of your students might be interested in it so here it isK: http://www.research.microsoft.com/srg/
Vincent Vigna says: Here is the web site to the free ware PC spectrogram utility I promised you in the previous class. The software is called 'Spectrogram'. It's really a nifty utility. http://www6.zdnet.com/cgi-bin/texis/swlib/hotfiles/info.html?link=1&fcode=000I04
Vincent Vigna also says: Another useful utility for those who may not have Matlab at home is 'waveflow'. 'Waveflow' is free ware that allows users to view, modify, and filter time waveforms of WAV files. It's easy to use, install, and remove plus it has a GUI interface that allows users to easily filter all or part of of the signal by simply highliting the waveform. Here is the web site: http://www.eupmt.upc.es/~cirvidf/download.htm
Marc Boillot says: seems like the free toolbox has some cool M files like Makevowel.m,FMpoints.m, whitevowel.m, and so on. Thought you'd find some interest in its applications as do I. see you in the movies. There is a new Matlab speech toolbox that is available for free. More information, documentation, and downloading links are available at http://web.interval.com/papers/1998-010/