T
he proliferation of coffee shops over
the last few decades can’t have
escaped anyone’s attention. Even
before the arrival of Starbucks in 1998, the
growth of the nation’s cafe culture was in
full swing. Between 1993 and 1997, the
number of coffee outlets in the UK
increased by an incredible 847 per cent. As
a nation, we consume a startling 95 million
cups of coffee every day, and the coffee
industry contributes over £17bn to our
economy, creating hundreds of thousands
of jobs.
Given the ubiquity of cafes – not just on
the high street but in workplaces,
universities, retail spaces, public buildings –
why do so many of them test people’s
patience with dreadful acoustics?
There are two contributing factors.
The first is reverberation. The second is
the Lombard Effect.Reverberation
When a sound wave strikes a hard
surface, it is reflected. This is known as
reverberation. The length of time it takes
the ‘sound pressure’ of this wave to fall by
60 decibels after the original sound has
ceased is known as the reverberation
time. In some environments, such as
auditoria, a certain amount of reverberation
is desirable in order to prevent sound
‘drop-off.’ In most environments, however,
it’s problematic.
Reverberation is prevalent in
environments with lots of hard surfaces.
Now, think of your typical cafe
environment: all those wipe-clean tables
and countertops; those wooden floors; all
that steel and chrome coffee-making
machinery; all that crockery. Reverberation
is guaranteed.The Lombard Effect
According to the UC Berkeley Phonology
Lab Annual Report (2008), “the Lombard
Effect is a phenomenon in whichspeakers alter their vocal production in
noisy environments, such as loud parties
or restaurants.”
In other words, in an attempt to be
heard over gurgling espresso machines,
clattering cutlery, clinking crockery,
piped-in music and other people talking, we
increase the volume and pitch of our voices.
This adds to the problem, leading others
using the space to raise their voices, which
means we have to raise our voices, which
leads to an exponential rise in volume. The
high levels of reverberation typical to coffee
shops massively exacerbate this problem.Solutions
The reverberation issue is the simplest to
resolve; and by solving this problem, you
may effectively combat the Lombard Effect
by virtue of reducing the overall noise in
the establishment.Paul Absolon of CMS Danskin Acoustics looks at solutions to reverberation problems in
noisy cafes, which are increasingly prevalent in the UKWhy the UK’s cafe culture
needs less reverb
The reverberation issue is
the simplest to resolve;
and by solving this
problem, you may
effectively combat the
Lombard Effect by virtue of
reducing the overall noise
in the establishmentINSULATION 71ADF NOVEMBER 2019 WWW.ARCHITECTSDATAFILE.CO.UK
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