I'm not sure I've ever heard of gimp being able to add sound to an
image. I thought it was more an imaging program. I know you can make
animated gif images with gimp by specifying a specific frame-rate
change on each layer. If you are using xp, look in your program files
for a program called windows movie maker, its a free program that
ships with the xp operating system and it allows you to add sound and
transition effects for images or groups of images. Movie maker is
probably more along the lines of what you have in mind. Its really not
that hard to figure out, and can produce some cool animation sequences
complete with sound.