I am working on a home project where the goal is to switch one channel of an mp3 player periodically to 4 different speakers, one at a time. I envision using a periodic audio frequency pulse on the other mp3 player channel to trigger the switching. In this case I would record sounds of nature (owls, birds, thunder, crickets, etc on one track. Between each segment I would record an audio tone when I want to switch to a different monaural speaker. The same rotation of speakers would always be used although it would be nice if a random rotation could also be selected.