We all know sound can factor into getting bass to bite, but that’s about all most of us have to go on. One sound does not fit all bass, fisheries or conditions.

We don’t hear this enough. Instead, manufacturers and anglers are usually both guilty of talking about sound and its application in the murkiest of terms. Nobody defines what constitutes “good” sound, and little to no instruction is given in terms of how to put sound to use on the water.

But strides are being made and they’re opening doors to bass anglers willing to listen.

The Science Of Sound

First, we need a crash course on exactly how bass hear. Biologists consider them “sound generalists,” which means they lack specialized ear structures and have a limited hearing range.
“Bass hear from about 10 Hz (a measurement of wave cycles per second) to 500 or 600 Hz—beyond that they’re essentially deaf,” says Keith Jones, Director of Research at the Berkley Fish Research Center. “They hear best at 100 to 200 Hz, which is a treble to bass sound.”
Although scientists understand the physical process of how bass hear, no one can say with absolute certainty exactly how they analyze that sound. But bass obviously do—after all, if noise of any kind attracted them, they’d do nothing but swim circles around lakes, chasing boats, ducks, swimmers, and the countless other non-prey things they hear in a given day.

So what differentiates a sound that attracts bass from one that doesn’t—or worse, repels them? Well, the answer isn’t entirely clear, even to scientists.
“What we can safely say is that for a sound to be an effective attractor it has to be one with a good portion of its range within the frequency spectrum bass can actually hear,” Jones says. Many lures do that. However, Jones says that the sound itself is likely far less important than how it’s used. “Just like humans, fish are set up to analyze sound according to temporal output (rhythm),” he says. “That might be far more important to them than the actual sound.”
To illustrate this, Jones points to a 1960s study by the Office on Naval Research. Trying to isolate what kinds of sounds attracted or repelled sharks, researchers recorded a grouper impaled and struggling on a spear. As expected, when the scientists played the recording underwater, sharks quickly approached it looking for food.
The researchers then attempted to isolate what characteristics made it pull in sharks and trigger feeding behavior. What they found was that any sound played continuously was quickly ignored. If, however, they made sounds broken by rhythmic pauses, they attracted sharks much better, but still not as well as the real thing. When the researchers broadcast sounds in a mixture of erratic pauses, everything changed. “The sharks just came running,” Jones says. “They loved that.” He says the same principle applies to bass.
“Even for humans, if we hear a constant sound, our brains are set up to automatically ignore it. If the sound is punctuated by alternating bursts and silence, you’ll stay fixated on it. Fish are the same.”

What does all this mean to anglers? First, don’t assume that a sound—no matter how cool it might seem—attracts bass. Truth is they might not even be able to hear it. And since most high-frequency sounds fall outside a bass’ hearing range, you’d usually be best served to incorporate low-frequency sounds in your presentation.

Going a step further, science would indicate that any sound audible to bass turns into meaningless white noise the moment it becomes a constant drone. So, the most effective way to utilize the sound produced by any lure is to vary your retrieve to break up the pattern.

Tackle Makers Respond

Manufacturers have caught onto this in the past couple seasons, developing baits with a single, large rattle in the chamber rather than several smaller ones. The result has been lures that create low-frequency taps rather than the steady scream emitted by traditional rattlebaits.
Truth be told, this “new” trend is actually the rebirth of an old standard. The XCalibur Xrk 75 One Knocker was first on the contemporary single-rattle scene when it hit the market during the 2007 Bassmaster Classic, but it’s a modernized version of the original Cordell Spot. “That bait had one large brass ball in its rattle chamber and produced a single knocking sound,” says Andy Carol, Executive Director of Sales and Marketing for Pradco Fishing. “That was it, but it worked.” Soon after the original Spot was introduced, however, lipless cranks with multiple rattles hit the market, locked in the public’s attention and redefined the rattlebait. The new lures caught fish, and it wasn’t long before the single-rattle versions were largely forgotten by anglers and discontinued by manufacturers. “But pros like Timmy Horton and Zell Rowland held onto those old lures and would rely on them when fishing pressured lakes where bass had been pounded by rattlebaits,” Carol says. “They kept asking us to bring them back.” So, XCalibur designers and pros set to work replicating and improving that single knocking sound while incorporating it into an Xr-style lure, maintaining the shape, sink rate and other characteristics. After experimenting with several designs and materials, they eventually settled on a tungsten rattle and a unique design that produced the optimal sound and rhythm. “Our rattle is actually not a ball but an anvil-shaped piece of lead with a tungsten post driven through it,” he says. “The anvil sways back and forth when the lure’s being retrieved or falling, and the tungsten knocks against the sides. The material gave us the precise, distinct sound we wanted.” XCalibur pros have seen the dividends. “I won’t pretend to tell you why, but these baits just catch fish,” says Talala, Oklahoma, bass pro Edwin Evers. “I’ve caught so many great, big fish on the One Knocker.” He says he’s had the best results fishing them in highly pressured situations. “If I’m fishing behind somebody, I know I can catch fish they missed.” Clack Attack Another major introduction has been the new Rapala Clackin’ Rap. The bait sports a metal rattle chamber that runs perpendicular to the centerline and is exposed at both ends, rather than being fully enclosed within the lure’s body. It holds a single large, steel BB, creating a deep, distinct sound. “We focused on creating a sound that was kind of ‘bright’ and kind of dull at the same time,” says tournament angler and Rapala field promotions manager Mark Fisher. To do it, Rapala turned to crankbait guru David Fritts. “First, we gave Fritts a bunch of Rattlin’ Rap bodies and turned him loose,” Fisher says. “He tried all kinds of different combinations of metals to come up with just the right sound. Once he had it down, we fashioned the first Clackin’ Rap in my garage using an old Risto Rap body.” After that, Rapala designers worked on the body shape, making the Clackin’ Rap thicker, with more rounded edges, than traditional rattlebaits like its Rattlin’ Rap. The changes aren’t merely cosmetic. “Flat baits are really easy for bass to throw. The new fatter body makes this much harder,” he says. To that end, Rapala also uses a No. 3 SureSet treble on the belly and a standard No. 4 on the tail. “The best rattlebait guys tend to trade out their factory hooks, replacing the belly treble with a much larger one, and the rear hook with a smaller one,” Fisher says. “Our big SureSet does the same thing, increasing the odds of getting a hook in the fish, while the smaller rear hook pins in the side of the jaw and holds the bass should the belly hook come loose.” Hybrid Rattler Bill Lewis Lures, manufacturer of perhaps the most popular rattlebait in history, the Rat-L-Trap, is also coming out with a low-frequency rattlebait. But there’s a twist. The Vibra-Trap (which was still awaiting introduction as of press time) is a hybrid of a multi- and single-rattle lure. It features an intricate sound system with one single BB “PowerBall Chamber” surrounded by several smaller multi-rattle chambers. “The motivation for the Vibra-Trap goes back to our Biosonics research,” says product developer Wes Higgins. Biosonics is the company’s electronic system that it claims attracts and triggers fish by broadcasting prey sounds underwater. “Our spectrograph results showed we could really improve the lower end of the sound spectrum,” he says. “We tried different size bearings and ultimately a single 6 mm tungsten ball in the PowerBall Chamber was the best overall fit—both in terms of sound and how it affected the lure’s action.” How To Fish Them Because these single-rattle cranks are virtually identical to their multi-rattle counterparts they can generally be fished the same way. But there are ways to wring more from them. According to Fisher, the best is to use a yo-yo presentation. This involves casting the bait, letting it sink to the bottom and then ripping it up, bringing your rodtip from 5 o’clock to 12, then following it back down to 5. “That part’s critical. You need to follow the lure down on the drop,” Fisher says. “The bait actually swims down between rips producing a slow ‘clack-clack-clack.’ The change in cadence triggers strikes, so be sure to let the lure swim all the way down between rips—don’t be too quick to pull it back up.” Fisher also recommends fishing the Clackin’ Rap on a stiff jigging rod and boosting your line to 17-pound mono from the standard 12. Evers also makes use of the XCalibur Xrk One Knocker’s tendency to rattle on the fall, but he prefers to use a straight retrieve with scattered pauses. “I like a reel-and-stop, reel-and-stop retrieve,” he says. Work in some pauses so the lure can fall.” Tapping Topwater Mineola, Texas, bass pro Kelly Jordon has also appreciates the tremendous effectiveness of the single single-rattle over multi-bearing ones. “It’s a retro deal. There were baits that created a single knocking sound years ago, but the fish got used to them,” he says. “Now it’s a sound bass haven’t heard a lot, especially on pressured bodies of water.” These reasons are among those that inspired Jordon to help design Lucky Craft’s new Sammy 105. He says the bait’s sole steel BB creates a deep tap that travels long distances in water, but he really likes it because of the way it marries the lure’s sound and movement. “Unlike a bait with multiple rattles, the 105 lets you really control how it knocks,” he says. “You can do this a little with other lures by varying the speed of your retrieve, but because this bait clacks every time you twitch your rodtip, you can precisely time each knock.” That sets up a deadly one-two punch in walking baits, which already have the built-in strike trigger of changing direction with every rodtip twitch. Comb-ining that motion with a loud rap at the same moment pushes fish over the edge. “It amps fish up and they just crush it instead of simply swiping at the lure or missing it, which are very common problems when fishing topwater walking baits,” he says. Jordon also credits the single BB for helping maintain a cadence because you can hear each time the bait turns. You can also control the volume by twitching your rodtip harder or softer. Goodbye To Rattlebaits? So do traditional rattlebaits still deserve a tray in your tackle box? Of course they do—a big one. They’re simply excellent bass lures and will likely always perform well, at times, in virtually any fishery. “For covering water, multiple-rattle baits are great tools,” Fisher says. “And I believe you sometimes absolutely need them to call fish out of vegetation.” It’s also important to note that even if you don’t get bass to actually bite a rattlebait, the sound they create often pulls in and fires up bass you’ll ultimately be able to catch on other presentations. Despite all this, it’s important to understand the lures’ limits. “All kinds of rattling crankbaits put off a wide range of frequencies; some in the range bass can hear and many others outside it,” says Jones. “But all of the sounds they make are nothing like what’s made in nature by prey.” And if a lake gets hammered by anglers fishing rattlebaits—multi-rattle or single—the fish will gradually become conditioned to avoid them. That’s why it’s essential to fish both styles of lures and use the kind that’s most appropriate to the fishery. Whichever you fish, remember how bass hear, and be sure to mix in plenty of erratic pulses to maximize the sound’s attraction. Knocking Carolina Rigs The single, loud clacking sound lure makers are incorporating into their rattlebaits also works when fishing softbaits on Carolina rigs. Anyone who lives to fish the ball-and-chain already knows this—sound has long been a pet part of every Carolina-rigger’s setup. Pro Kelly Jordon takes this to the extreme, however. “I like to use two 1⁄2-ounce or three 3⁄8-ounce tungsten weights rather than a single 1-ounce lead sinker in my Carolina rigs,” he says. “When those weights slam together that’s the loudest rig you can get.” Jordon says this gives him a huge edge when dealing with pressured fish, or even when fishing right behind another angler.
“I can’t tell you how bad I can out-fish someone right next to me who’s fishing a normal Carolina rig. I mean I’ll beat them bad, especially in deep water.”

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