Logitech 910-004913 Product Data Sheet

Silent Mice - White paper

By Logitech, August 2016

Executive summary

Several studies have shown that noise can affect human health and productivity in a negative
manner (Banbury & Berry, 1998; Maxwell 2001). To reduce the disturbance induced by
computer mice, Logitech has launched new models integrating technology that lowers the noise
level.
New click switches, new gliding feet and new internal construction are all part of the solution to
make the new mice quieter. As a result, independent tests commissioned by Logitech have
shown that the noise emitted by the clicks has decreased by more than 90%. As evidence of
this achievement, Logitech is the first mouse company in the world to receive the Quiet Mark
certification, an international mark of approval award program from the UK Noise Abatement
Society recognizing technology that has been designed to reduce noise.

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Introduction

According to Julian Treasure, renowned sound expert, noise affects us physiologically,
psychologically, cognitively and behaviorally (Treasure, J. 2009). Most of the sound around us is
unintentional and unpleasant. Although, unfortunately, many people are unaware of the possible
negative effects of noise, being unable to get away from it can be extremely damaging for health
and productivity .

According to a study published by Banbury and Berry (1998), productivity is reduced by 66% in
open-plan offices, a massive decrease that is mainly due to the negative effects of sound.

With a goal of improving health and productivity, Logitech has decided to tackle the irksome
sounds of one of the most used computer companions by introducing “Silent Mice”.

Problem

Besides affecting the health and productivity of its user (Maxwell, 2001), the sound of a mouse
also impacts people in the vicinity. With the prevalence of open-space office layouts and
conference calls, the clicking sound can be highly disturbing to a large number of people. In a
home environment, using a loud clicking mouse when partners, children or roommates are
going to bed can actually prevent them from falling asleep.

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Noise Abatement Society official website: www.noiseabatementsociety.com

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Solution

In computer mice, the sound comes from three distinct sets of components: 1) the feet, when
gliding the mouse on a mousepad or table, 2) the wheel module, when scrolling up and down,
and especially 3) the switches, when clicking on the left, right or middle button.

Figure 1: Bottom and side views of Logitech M330

Through technological advancements, Logitech has considerably reduced the sound emitted by
these components.

Technological advancements

Switches

The switches used in Logitech Silent Mice are made of a rubber actuator that dampens both the
vibration and the sound. A red plastic cap covers the rubber actuator to improve the switch’s
tactile feedback and lengthen its lifespan. The switches used by Logitech have a lifespan of
5 million cycles, on par or often better than most of the non-silent mice found on the market
today.

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Figure 2: Assembled silent switches - Figure 3: Dismantled silent switches

The new switches significantly reduce the clicking sound while keeping a tactile feedback similar
to that found in non-silent models.

Scrolling

Logitech used a mechanical encoder for its M330 Silent Plus Mouse model. As compared to an
optical module, the mechanical encoder has the advantage of considerably reducing the sound
level while maintaining a satisfying feeling of ratchets when scrolling the wheel up and down.

Feet

Logitech normally uses gliding feet made of Unsaturated Polyester (UPE) material for its lower-
and middle-range mice, and Polytetrafluoroethylene (PTFE) for its higher-end range. UPE feet
provide good performance at a reasonable price, while PTFE feet provide a better gliding
performance.
For its Silent Mice, Logitech opted for Plastic Lumber (PL) material, which proves quieter and
more durable than other materials such as UPE and PTFE.

Plastic part design

Most mice have a large empty cavity under the keyplate. While it is often necessary to give the
mouse a certain volume to achieve the desired comfort level, this empty chamber also amplifies
the noise created by the clicking switches, scrolling wheel and gliding feet. To further reduce the
noise level, Logitech added plastic ribs within its Silent Mice. Like a noise barrier on the side of
the highway, these inner walls dampen the sound and reduce the echo created within the
mouse.

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