What Does "90% Quieter" Mean on a Silent Mouse?

It means the click puts out roughly a tenth of the sound energy of the mouse it was measured against, at least as Logitech defines it. Your ears don't hear in energy, though. To them, a cut that size sounds somewhere between a third and half as loud.

That's still a real difference, and at a late-night desk or on an open mic it's a welcome one. It just isn't the near-silence the number seems to describe.

Picture a room of people clapping. Ten people clapping together make ten times the sound energy of one. They don't sound ten times as loud, though. By the usual rule of thumb, they sound about twice as loud.

Decibels keep track of this. On that scale, every 10 dB is a tenfold change in energy, so a 90% cut works out to exactly 10 dB.

How much quieter does 10 dB sound? The long-standing answer is about half as loud. Later research found that a drop of around 6 dB can already sound half as loud, which would put 10 dB nearer a third. Both rules were worked out on steady sounds rather than quick clicks, so treat them as a guide. Either way, you end up a long way from a tenth.

Logitech reaches for a similar picture in a support article about one of its quiet-click mice. It says you'd need more than ten of the newer mouse clicking at once to sound as loud as the older one. That's the clapping room again: ten times the energy, not ten times the loudness.

An 80% claim follows the same logic. It's about 7 dB, which sounds somewhere between a little under half and about three-fifths as loud.

Not as a measurement. Comparing sound energy is a standard way to compare two sounds, and it's how Logitech defines its figure. The trouble is only in the reading. "90%" sounds like a statement about loudness, and it isn't one.

Logitech set out its method in a 2016 white paper on its silent mice. It's linked in the sources at the end if you like seeing the working.

An outside lab put the mice in an anechoic chamber, a room built to soak up echoes. The meter sat one metre from the mouse and measured the left click from four angles. Logitech then turned the difference in sound power into a percentage.

The silent mouse came out a little over 11 dB below the standard one, which Logitech reported as a 93.3% reduction. One detail stands out. Logitech set the silent mouse's loudest click against the standard mouse's quietest, the comparison that gives the silent mouse the smallest margin.

Not every claim comes with that kind of detail. Some name the comparison mouse and the distance. Plenty give a percentage and leave it there.

Ninety percent quieter than what? That question matters as much as the number.

In the claims that name one, it's another mouse from the same maker. Sometimes that's a basic office mouse with an ordinary click. Sometimes it's the same model's previous version. Each figure is a step down from its own starting point, so two mice can both claim 90% and still land at different levels, the way two "half off" price tags can still leave you paying different amounts.

That's why the percentages don't rank mice against each other. Our guide to silent-click mice, linked at the end, shows which mice carry a quiet-click claim and, where the maker says, what each one was measured against.

Mostly the main buttons. A published test may measure the left click alone, and some spec sheets say their figure is for the left click.

On some mice, the spec sheet calls the left, right and wheel clicks silent and lists the side buttons without that word. Scrolling, and the slide of the mouse across the desk, are separate noises again. A few mice claim to quiet those as well. Plenty of claims don't mention them.

So if you lean on the back and forward buttons all day, check which buttons the quiet label names before you buy.

The percentage travels well. The level doesn't.

The lab figure is taken one metre away in a room with no echoes. At a desk, your ears are usually closer than that, and the person at the next desk is further away. In open space, sound drops about 6 dB each time the distance doubles. A real room bounces sound off the walls and the desk, so indoors that rule is only a loose guide.

What does carry over is the comparison. Swap an old mouse for a quieter one in the same spot and the new one keeps roughly the same margin. That's also why a "silent" mouse can still be heard in a quiet room late at night. Quieter is a comparison. Silent, in the everyday sense, would be an absolute.

Start by translating the percentage. 90% is about 10 dB, which your ears hear as somewhere around a third to half as loud as the comparison mouse. 80% is about 7 dB.

Then look for what it was measured against, and at what distance. A claim that names both is telling you something specific. A bare percentage tells you the maker found a difference, and not much more.

Check which buttons the label covers, especially the side ones if you use them.

And read "quiet clicks" with no figure as a description. It may well be fair. You just can't compare it with anything.

Once you know how quiet you need, our guide to silent-click mice sorts the options by shape, from compact mice to trackballs. When one looks right, try it on the board next to a keyboard and a headset, and see how the whole desk comes together.