Sound can help on some lakes. I once saw some guys on LOTW doing laps around their fish house with their truck. I thought they were nuts until I went and talked to them and saw that it worked. They got the idea because they would catch walleyes every time a truck pulled up to their house.
Jamming some good tunes can be deadly on suspended crappies. The String Cheese Incident seems to work best. We took first in a panfish tournament with that tactic.