Many lures have rattle chambers, which create quite a racket. In some cases, in fact, you may not only feel the vibrations in your rod but also hear the rattles as the lure moves through the water at relatively far distances. Some people love rattling lures, and utterly swear by them. But, do they really have a fish-attracting effect?
First, consider what fish hear: low frequency sounds, usually in the 500 to 1000 Hz range. Do rattles and clacks fall in there? Quite often, you bet. Next, consider what sorts of sounds a struggling baitfish makes. You can Google “struggling baitfish underwater recording,” and listen to a number of recordings for yourself. It’s quite illuminating, because the majority of the sounds those baitfish make are more or less like a clicking and clacking – not terribly far off from the sounds those rattle chambers produce.
Now, consider the fact that along with hearing via an inner ear, fish sense vibrations in the water with their lateral line. These are generally even lower frequency, from 100 Hz down. The sense is primarily used for detecting motion and activity in the water, and helps the fish both with schooling behaviors and also with locating predators and/or prey. Generally the lateral line senses movement that’s close by. So if a lure’s frequency is low enough, it stands to reason that fish will not only hear it, but also feel it moving through the water.
So, back to the original question: do rattling lures work better in saltwater? It all depends on who you ask, because truth be told, no one’s ever done a scientific study on the exact effect rattles in a lure have. (Of course, you know exactly what the lure-makers will have to say about this if they build lures with rattles in them!) Ask around, however, and you’ll find an awful lot of anglers who live by lures like Rat-L-Traps, Shad Raps, and so on. Do they – or we – have proof that the rattles help? Heck no. But do many of us have a strong feeling that these things are very effective at generating strikes when other lures may fail? Youbetcha.