So my parents flew accross the country to visit me and I am converting all their old home videos to DVD using iMovie. There's no sound on the movies so they sit infront of my new iMac to narrate and I capture on Garageband. I know very little about what I'm doing but seem to do an ok job except there's this annoying thumping in the background... possible some tempo thingy? I'm sure everyone knows what this noise is but me since I have no music knowledge. But does anyone know if it's possible to get rid of it and not destroy the narration? Thanks for the help!