My thanks to all of you for your suggestions and resource information. My real purpose in doing all this is more curiosity just to see what can be done with relatively simple code now that systems are fast enough to do truly useful things with audio. I have used the pitch adjustment control in sox and it is astonishing how well it can tweak the speed of a tape up or down a bit to make it correct. Tim Chase writes: >The "sox" package has an >option for speeding up playback without changing the pitch. I am going to have to look at the man page again. What effect does this? Thanks again. Martin McCormick _______________________________________________ Blinux-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/blinux-list