After the shot, the arrow is gone but the string is not. The limbs snap back, the cams rotate through their cycle, and the string is left oscillating at its natural resonant frequency — which for a typical compound string falls squarely in the audible range. That oscillation is the twang. It radiates sound into the air, transfers vibration through the riser and back into your grip, and continues until the string's stored mechanical energy dissipates. String silencers exist to make that dissipation happen faster.
There are two physically distinct approaches to that problem, most archers conflate them, and they do not work the same way.
Weights and dampers — two different mechanisms
String weights — cat whiskers, monkey tails, beaver balls, and anything else that adds fibrous or rubber mass directly to the string strands — work primarily through mass loading. Adding mass to a vibrating string shifts its resonant frequency downward. Lower frequency means longer period: the string oscillates fewer times per second, which means less acoustic energy radiated per unit of time. The fibrous strands also dissipate energy through aerodynamic drag as they flap and move with the string — a secondary effect, but a real one. The mass is the primary mechanism.
String dampers — rubber leeches, polymer clamps, viscoelastic pads clamped around the strands — work through internal material friction. Every time the string flexes through the damper, the viscoelastic material deforms slightly and converts some mechanical energy to heat. These do not shift the resonant frequency as dramatically as mass loading does, but they dissipate energy efficiently each cycle. A rubber leech converts a fraction of each oscillation into heat rather than sound.
Most products marketed as "string silencers" blend both mechanisms to varying degrees. A rubber-and-fiber monkey tail adds mass (frequency shift) and includes material damping in the rubber core. A simple cat whisker is mostly mass-loading. A plain rubber tube clamp is mostly viscoelastic damping. Understanding which mechanism dominates in a given product tells you what it actually does to the string's behavior.
String stops are a third category worth separating out. They physically arrest the string after the shot by placing a post directly in the path of string travel. The string contacts the stop, is mechanically halted, and the oscillation is interrupted rather than absorbed. This is a fundamentally different approach — highly effective for eliminating the first large-amplitude oscillation — and is not really in competition with string silencers. A string stop and a pair of silencers serve different purposes and work together rather than replacing each other.
Why placement matters — vibration modes and antinodes
A vibrating string doesn't oscillate in a single simple motion. It vibrates in modes — each mode a distinct standing wave pattern with specific points of maximum motion (antinodes) and specific points of zero motion (nodes). The fundamental mode has one antinode at the center of the free string length and nodes at each end. The second harmonic has two antinodes at the quarter-points and a node at the center. The third harmonic has three antinodes and nodes at the third-points. All modes are present simultaneously after the shot.
This is why placement is not arbitrary. A silencer placed at a node sits in a part of the string that barely moves — it contacts essentially no vibrational energy and dissipates essentially none. A silencer at an antinode is riding the string's maximum motion every cycle. It absorbs energy continuously until the vibration damps out.
Manufacturers place silencers roughly 25 to 33 percent of the free string length from each end. This is a pragmatic compromise — it hits the antinodes of the second and third harmonics, avoids the node at center where the nocking loop lives, and still intercepts a meaningful fraction of the fundamental's displacement. It's not optimal for any single mode, but it's effective across all of them simultaneously.
A silencer placed exactly at the center of the string — where the loop is — would be in the antinode of the fundamental but in the node of the second harmonic. A silencer placed at the exact quarter-point would sit in the antinode of the second harmonic but near the node of the third. The standard placement is the best available real-estate given that the nocking point is non-negotiable.
How much quieter is it, realistically
Measurably, but not dramatically. The honest answer requires distinguishing between what is actually happening acoustically and how it is perceived.
Well-placed silencers on a bow with significant string ring can reduce the post-shot string noise by roughly 3 to 6 dB. Three decibels is barely perceptible as a loudness change; 6 dB is clearly noticeable. The bigger perceptual effect is often the pitch shift rather than the amplitude reduction. Lower frequency string oscillation — produced by the mass loading — sounds quieter to human ears even when measured amplitude hasn't dropped proportionally, because high-frequency vibration radiates sound more efficiently and is more irritating to human hearing. The bow goes from a sharp, penetrating twang to a lower, shorter thump. That perceptual shift can feel more significant than the raw dB numbers suggest.
The most dramatic improvements happen on bows that are otherwise well-built but still have an audible, high-pitched string ring — usually bows with longer string lengths, high brace heights, or less aggressive cam timing. On a bow already dampened with good limb stops, a heavy riser, and internal limb dampeners, string silencers are working on what's left after everything else has already done its job. The marginal gain is real but smaller.
At hunting distances, even a modest reduction matters for a different reason. The launch sound is what triggers the deer's orienting response before the arrow arrives. A silencer that reduces the sharpness and amplitude of that sound slightly weakens the alerting stimulus. It does not prevent string jump — nothing available in current archery equipment prevents string jump — but it may reduce the completeness and speed of the orienting response, which in turn affects the severity of the escape response. The value there is marginal but not zero.
The speed cost — and why it's worth understanding
This is the side of the equation most archers don't account for. The bow accelerates everything attached to the string during the shot: the string itself, the serving, the D-loop, and any silencers. That mass has to be moved from standstill to full string velocity in the same power stroke that launches the arrow. Energy that goes into moving the silencer is energy that does not go into the arrow.
The relationship between string-side mass and speed loss is roughly parallel to the relationship between arrow weight and speed: each additional grain on the string costs approximately the same as a grain of additional arrow weight. A pair of typical cat whisker or monkey tail silencers runs somewhere between 30 and 70 total grains depending on the style and size. That's enough mass to cost 3 to 8 fps in practice, with real-world field tests consistently showing losses in the 4 to 6 fps range for average-weight silencers.
That speed doesn't disappear — it goes into accelerating the silencer mass, and then into the silencer's internal damping as that mass decelerates back down. Some of what you're paying for in string silencers is exactly the mechanism that makes them work: the energy they absorb had to come from somewhere, and it comes from the arrow.
Reasons to run them — reasons to pull them
This is a setup decision with real tradeoffs, not a universal right answer.
Run them. You're hunting, or your bow has a harsh ring
For a hunting setup, string silencers make sense. The noise reduction is marginal in absolute terms but not irrelevant at 20 to 30 yards from an alert animal. A slightly quieter launch sound is a slightly weaker alerting stimulus. A lower-pitched residual vibration is less likely to cause a full-commitment escape response in an animal that's already heard the shot. The speed loss — typically 4 to 6 fps — matters less when you're shooting at 20 to 35 yards than it does at 60 and beyond. If your bow has an audible, high-pitched string ring after the shot, silencers are also doing real work on felt vibration and bow noise as a pure comfort matter.
Pull them. You need to know your exact speed
For 3D archery, outdoor target, or any setup where your sight tape was built from measured field data, adding or removing silencers after the tape is set introduces error. A 5 fps speed loss is not a trivial sight-tape variable. At 20 yards the mark shifts by a couple hundredths of an inch — hard to notice. At 60 to 80 yards the error compounds with distance and can move the mark enough to cost you a 10-ring. If you've shot a ballistic model from your own field marks, your marks already include whatever silencers were on the bow at that time. Changing the silencer configuration means your tape is calibrated to a different bow than you're currently shooting.
Competitive archers — indoor, outdoor target, 3D — typically remove string silencers for the same reason they don't add unnecessary accessories: every uncontrolled variable is a potential inconsistency, and the speed loss is not offset by any benefit that matters in competition.
The one thing most people skip
String silencers are installed at the factory, swapped by dealers, and changed by archers with no chronograph check before and after. If you've never confirmed what your silencers are actually costing you in fps, that's a ten-minute test worth doing. Shoot a group over a chronograph, pull the silencers, shoot again. The number you get is real — not an estimate from a table. That number is what your sight tape was or wasn't built around. Knowing it is more useful than any general figure this article or anyone else can give you.