I cannot figure out any consistent pattern for when this icon appears in the middle of a slide. Sometimes in is on the slides where the music file begins, sometimes it is not. Sometimes it is oon the continuation slides, sometimes it is not. I should add that, to eliminate abrupt endings to the music files, we continue a music animation one extra slide so that it overlaps the new music file beginning on that slide. That is, if we have a music animation to be played on slides 1 - 10, then another music animation to play on slides 11 - 20, the first music animation is set to run for 11 slides, not 10, even though the new music animation begins on slide 11. This makes for a pretty good segue of the music. My issue with the megaphone icon does NOT seem to be related to this overlap of music files, but I thought I should mention it.
You just cannot have that stupid megaphone sitting there on a high-end presentation. Anyone know how to make it completely go away and never, ever show up in the slide show?