I purchased a bucket of these pens off ebay for about $0.35 each. They let you record about 25 seconds of sound, and then play it back. The kids love them and wander the house making 'noises' and playing it back over and over and over and over...
I've taken some of the pens, easily soldered wires to the "playback" button inside the pen, and removed the pen (ink) part. As you can see in the picture, a simple bolt fits right into the threading for the pen insert - and the bolt can be used to attach the unit to the fish alarm frame. Easy and cheap! The playback wires are triggered by the fish alarm sensor button, and play a pre-recorded message... "Bert! Bert! Your getting bit!". Its pretty loud, too, without adding an amplifier. Problem is, my bare-footed fishing buddy may require a mild electric shock to roust him from his slumber...
