In fact, I first became a believer after actually listening to the sounds. I used to own an aquarium company, basically I would setup fresh and saltwater aquariums for companies lobbies and maintain them. If you've ever fed a fish live bait you'll be amazed how well you can hear that on the outside of the aquarium, kinda sounds like they're eating potato chips. crunch, crunch.
These are some of the sounds incorporated with the Hydrowave.
I still am learning when and where and why, but I'm telling you when they a collide it makes life-chaninging days on the water. Plus, it doesn't hurt you, if it gives me one more bite a day, it'll pay for itself in no time.