麻豆传媒

Barely audible

Question I鈥檝e heard that the levels of noise in some busy restaurants are now
so high that they exceed industrial safety levels. Is this true? If so, why? Is
it a result of the current vogue, in Britain at least, for minimalist furniture
and bare floors that reflect sound? And are some kinds of noise more damaging
than others?

Charlotte Jemm

Answer It does seem to be true. Although we can find no data on the topic,
our own research suggests that the level of noise in some crowded modern
restaurants is now so high that waiters ought to consider donning industrial ear
muffs to protect themselves from possible hearing loss. Regular diners might
like to take theirs along too, although we hope that restaurateurs might make
life easier by opting for one of the low- or high-technology solutions suggested
below.

To examine the dangers of eating out, our investigative team ate lunch at a
sample of the best central London restaurants, taking along a decibel meter set
for the frequencies that match the responsiveness of the human ear (dBA range).
We also visited several pubs and wine bars and recorded a minimum of 10 sound
level readings at intervals of 5 minutes during each visit. The chart shows both
the average sound level and the highest reading taken at each location.

The results were astonishing. Crowded restaurants that follow the current
fashion for bare concrete floors and ceilings can be unbelievably noisy. In
these restaurants the sound of conversation is reflected back into the room with
little loss of energy. Although none of the nine restaurants we visited played
music, average values throughout the meal in four of them were 88 decibels or
more; and at one West End restaurant we recorded a peak value of 97dB.
Curiously, that鈥檚 the sound level that the official government guide, The Noise
at Work Regulations, describes as made by a 鈥減ighouse at feeding time鈥�, although
we hate to draw this comparison.

Here鈥檚 a better way to appreciate the sound levels. At around 80 dB, diners
start to have to raise their voices to be heard by a small group. That in turn
pushes up the noises levels. By the 85 dB mark, a table of six diners will tend
to break into two groups of three conversationalists, because it becomes
impossible for everyone to hear one another. By 90 dB, conversation will break
down further, with communication limited to shouting into the ear of the person
next to you.

Prolonged conversation in environments where the noise level is above 80 dB
can also lead to sore throats and laryngitis as speakers have to bellow to be
heard. Above 85 dB you risk hearing damage, with the level of risk dependent on
the length of exposure and the sound levels. The risk rises sharply with the
sound level鈥攆or every 3 dB rise in sound level, the safe exposure time
falls by half. Under current British regulations, employers should take action
where employees鈥� daily personal noise exposure is above 85 dB for an 8-hour
working day.

In contrast to bare-walled modern restaurants, traditional restaurants with
carpeting, curtains and tablecloths are much safer for your ears. None in our
sample exceeded 75 dB, with conversation perceived as a low hum. Pubs could be
very noisy, but only when packed with standing drinkers and playing loud
music.

There are a couple of solutions for those running crowded, minimalist
restaurants. One would be to turn back to the great low-tech traditions of the
past. In Britain that would mean covering up bare concrete walls with nice thick
flock wallpaper, coating the ceiling with plastic sound-absorbing tiles, and
putting a heavy carpet on the echoing wood floors and long chintz tablecloths on
the pine tables. It might be unfashionable but it would represent a return to
good acoustic design.

If style gurus find such changes intolerable, high-tech solutions are also
possible. Most simply, waiters who are subjected to high noise levels for the
longest time could be given industrial ear muffs. Customers would then, of
course, be forced to point at what they wanted on the menu but this could make
both the ordering process more efficient and avoid embarrassment for those
unsure of the correct pronunciation of such foodstuffs as grenouilles and
shiitake.

Really modern restaurants could take a step into the future and provide both
waiters and customers with noise-cancelling headphone-microphone sets like
those used by jet-fighter pilots. These sets take in both the surrounding noise
and, from a microphone close to a speaker鈥檚 mouth, the surrounding noise plus
voice. The two signals are then subtracted from one another, leaving only the
voice running through the headphones. Their high-technology look might fit
nicely with the ambience of the concrete and chrome restaurants and let them
pack in even more diners, raising their profitability.

Of course, scientists will wonder why people bother to fight for seats in
restaurants where they can barely make themselves heard. This illogical
behaviour will be the subject of a further study by the 麻豆传媒 team, once
our expense account has been replenished鈥擡d

Shout it out

Question Has anyone ever done any research on the relationship between noise
and aggressive behaviour? I hate to admit it, but when I am subjected to
excessive noise, such as that produced by lawnmowers, motorbikes, rubbish trucks
or screeching children, it makes me want to get a gun and shoot the source. As a
55-year-old woman, I obviously will not give in to that desire. But I have
sometimes asked myself if the oft-quoted increase in violent behaviour is partly
caused or triggered by noise? And, if this is so, is there more violence in
areas near airports, big roads and other such places?

Am I alone in noticing this peculiar effect, or is there any research to
support my suggestion?

Almuth Hauptmann

Answer Laboratory studies have found that unpredictable and uncontrolled
bursts of noise increase the aggression of angry participants (see reference 1).
There are also links between school violence and classroom noise levels,
although there are clearly problems with such correlations (2). Perhaps it is
more revealing that the administration of bursts of loud noise is used to
stimulate aggression in many psychological studies (3).

Jon Sutton

Department of Psychology

Glasgow Caledonian University

Answer There is plenty of evidence from questionnaire surveys that
environmental noise causes annoyance but it is not clear that this leads to
aggressive behaviour in general. Some studies have found that areas with a lot
of aircraft noise are linked to high rates of suicide and homicide compared with
quieter areas, but they have not always adequately controlled for social
deprivation in noisy areas, which may be a more potent predictor of increased
mortality than noise.

Incidents are reported where people attack others because of noise they were
making. As far as I know there has been no systematic study of these but noise
may be merely the trigger in someone predisposed to violence.

Stephen Stansfield

Department of Psychiatry

Royal London School of Medicine and Dentistry

Answer By way of anecdotal evidence, I like loud noises. A burst of noise
from a fire alarm, pneumatic drill or jet engine at close quarters gives me a
feeling of euphoria followed by a general sense of well being.

Mark Taylor

Institute of Astronomy

Cambridge

Answer Noise will not affect everyone in the same way, as Mark Taylor鈥檚
response above makes clear.

Although there has not been a large body of research on the topic, available
studies suggest that individual noise sensitivity is a stable personality trait
covering attitudes towards a wide range of sounds (4). If you are a
noise-sensitive person, the modern world can be hell鈥擡d

Fizzy fallacy?

Question Champagne will keep its fizz if a spoon is suspended in the neck of
the bottle as long as the spoon does not touch the liquid. Why is this?

Helen Kirkbride and Jo Fowler

University College London

Answer Variants of this question have been sent in many times over the years
but we have never published them because the idea that a spoon (or, as sometimes
suggested, a silver spoon) could stop champagne from going flat just did not
seem sensible.

But not wishing to seem narrow-minded, we tried a quick test one day. To our
astonishment, we found that a half-full bottle of champagne left in the office
fridge with a teaspoon slipped into its neck easily kept its fizz for 12 hours
and was still sparkling after 24 hours.

Had we discovered a new principle of physics? Sadly not. All we had
discovered was the old principle of how easy it is to be misled by uncontrolled
experiments. When we repeated the experiment more carefully, asking people to
blind taste champagne which had been opened and stored either with or without a
suspended spoon and rate the fizz against freshly opened champagne on a scale of
0 to 100, the spoon was found to have no effect at all. An opened bottle of
champagne just keeps much longer than most people think it will. As the graph
shows, both opened bottles decreased in fizz at exactly the same rate and were
not rated as totally flat until approximately 96 hours after opening! As few
people will regularly have two bottles of champagne open at the same time, if
you have stored yours with a suspended spoon, you鈥檒l probably attribute its
unexpected longevity to the spoon.

It鈥檚 not uncommon to attach significance to apparently linked events when
they are rare and there is no control data. Every day, you鈥檒l hear people say:
鈥淗ow amazing, I was just thinking of you and then the phone rang and it was
you鈥︹�� Although we鈥檇 all like to be telepathically connected to our friends,
what you never remember, of course, is the number of times the phone did not
谤颈苍驳鈥抬诲

Suck it and see

Question I have heard it said that if you drink beer through a straw you will
become intoxicated more quickly. Many of my friends have heard it too. Is it an
urban myth or true and, if so, why?

Haitsu Shiroyama

Answer I don鈥檛 know if you get drunk more quickly by the effect of drinking
through a tube, but if it is a myth, it is a long-standing one. In Chaucer鈥檚
Canterbury Tales (written in the late 1300s), the Manciple says (in the Prologue
to the Manciple鈥檚 tale) of the cook鈥檚 drunkenness:

鈥淵ou鈥檇 think he had been drinking monkey-wine, And that鈥檚 when one goes
playing with a straw!鈥�

Other lines refer to the cook鈥檚 colour, breathing, etc. In the notes on the
lines, the translator Nevill Coghill refers to a letter he had received from a
young doctor at the London Docks: men were occasionally brought to him for
attention after having been found insensibly drunk in a wine warehouse, with
similar colour and breathing problems to those described by Chaucer. The doctor
was told that the they had been 鈥渟ucking the monkey鈥�, which meant drilling a
tiny hole in a cask of wine and sucking it through a straw.

Sue Johnson

Lisvane, Cardiff

As a former student I can testify to the definite financial advantages of
drinking beer through a straw. For an even cheaper inebriation, beer can be
鈥渆aten鈥� from a bowl with a soup spoon.

Chris Hope

Welwyn Garden City, Hertfordshire

The Russian version of this old belief, that drinking alcohol in small
quantities enhances the effect drastically, says that nobody is capable of
drinking 40 thimbles of vodka, though that amounts to only about 150
millilitres.

Michael Shusser

Caltech, Pasadena, California

We decided that some preliminary research was needed, although of course we
stress that no one should drink beyond safe limits (which means not at all if
driving a car).

To measure the effect of alcohol we adapted three police Standard Field
Sobriety Tests, described to us by Wayne Jones of the National Laboratory of
Forensic Toxicology in Link枚ping, Sweden. The tests were the number of
times a subject stepped off a 3-metre-long straight line when asked to walk
along it and back, the time each person could stand on one leg with his or her
eyes closed, and the number of errors made in five attempts to touch the tip of
their nose with eyes closed.

Ten volunteers came forward from the office for two evenings of tests. Beer
was the preferred drink and all our volunteers performed worse if they consumed
their alcohol through a straw, rather than swallowing it, with the number of
seconds they could stand on one leg halving. These results are only suggestive,
of course, as all subjects obviously knew when they were drinking through a
straw and could simply have adjusted their expectations.

If the effect is real, what is the explanation? It could be that drinking
small quantities helps to mix in air which carries alcohol to the nasal cavity
where it could be absorbed rapidly into the brain, or perhaps that a more even
flow of alcohol boosts absorption efficiency. Only an objective study, perhaps
recording blood alcohol levels, could begin to answer these questions.

Pipe dream

Question In one of the earliest issues of 麻豆传媒, a scheme was
outlined for the long-distance transport of solid goods by pipeline. The idea
was for a national network of cylindrical pipes about a foot in diameter,
through which cylindrical containers up to three feet long would be propelled by
fluid. The author maintained that many goods carried by road or rail could be
transported by this method. The original plan had a pipeline terminal in each
town where there would be a depot to provide distribution. If this proved
successful, the pipes were to be extended to homes so that food and mail could
be delivered. Does anyone know what became of the scheme?

Roger James

Answer This question appeared in the very first Last Word column on 26 March
1994 and has been waiting for an answer ever since. Back in the issue of 7
October 1965 we did indeed speculate that many goods鈥攏ot just oil and
gas鈥攃ould be transported by small pipelines, easing congestion on roads.
The article, written by C. W. N. McGowan was in part based on an Institute of
Petroleum lecture by the late John Loudon, who went on to be chairman of Royal
Dutch Shell. Pipeline freight transport has not so far experienced such an
illustrious career, even though it flowered briefly in the Soviet Union and
arguments for it are now stronger than ever. Propulsion and pipeline-laying
systems have been greatly improved and computers could now provide sophisticated
routing for cargo. And, as traffic congestion grows, the idea of delivering
goods through underground pipelines seems wonderful.

Will we ever seen one built? Future developments are likely to come from two
places: the Netherlands, where an international conference on underground
freight transportation will take place in September at the same time as the
Dutch parliament discusses an initial project that could link Amsterdam鈥檚
Schiphol airport by freight pipeline to the flower market at Aalsmeer; and
Missouri, where a project to test the transport of coal in long-distance
pipelines is under way.

A couple of older, simpler systems are still used in Japan. The Sumitomo
Capsule Liner is the best known. It carries limestone from a mine in Tochigi
Prefecture straight to a plant 3.2 kilometres away and is of great benefit to
local residents because it keeps heavy truck traffic off their village roads.
Although the pipeline is just a metre in diameter it has been delivering 2
million tonnes of freight a year for almost 20 years. The freight is carried in
wheeled capsules propelled by air pressure generated by large blowers.

Its designers learned from Soviet work. During the 1970s, several pipeline
freight systems were built. One 45-kilometre system in Georgia carried 2 million
tonnes of minerals each year.

The largest research institute devoted to pipeline transport is now to be
found at the University of Missouri-Columbia. The Capsule Pipeline Research
Center, run by Henry Liu, is investigating two propulsion systems: pneumatic and
hydraulic.

Pneumatic systems, propelled by air pressure, need booster fans along the
length of the pipeline unless it is very short. That causes problems because
freight has to be sent around a bypass tunnel when it reaches the booster
fan.

A neat solution owes much to pioneering work by M. Carstens of the Georgia
Institute of Technology and William Vandersteel, a New Jersey engineer and
backer of TubeXpress, a system designed for long-haul delivery of freight
through 2-metre-diameter pipes. Vandersteel patented the idea of tube capsules
which fitted closely inside the pipe and acted as pistons. By propelling these
capsules with linear induction motors, they increase the air pressure in the
tube ahead of them, forcing other capsules up ahead to keep moving. Liu explains
that such pneumatic systems can carry freight cars at up to 72 kilometres per
hour. As they run 24 hours a day, this means they can beat the average
inter-city delivery times of a truck.

Liu鈥檚 main focus is on the much slower hydraulic 鈥渃oal log鈥� pipeline system
which could offer an immediate economic advantage. In Missouri, coal for power
stations has to be carried by rail over 1000 kilometres from mines in Wyoming
and Colorado. If Liu鈥檚 system were used, the coal would be compacted into short,
cylindrical 鈥渓ogs鈥� which would then flow along a water-filled pipeline at around
11 kilometres per hour.

A 50-centimetre pipeline could carry 18 million tonnes of coal a year, enough
for up to five large power plants, says Liu. He has almost finished a pilot
project and if it works well, a commercial system could be under construction in
two years. Over distances greater than 30 kilometres, he believes that freight
pipelines will prove more economical than trucks.

Elsewhere, the dream of pipeline freight transportation and the benefits it
could bring to crowded urban environments remains alive. In the Netherlands,
research has been going on at the Delft University of Technology since the
1980s, on the control technology needed for electric-powered cars running in a
5-metre-diameter tunnel connecting the main international airport to the flower
market and to a freight terminal. Johan Visser, who runs the project, says that
similar systems running in 3-metre-diameter tunnels could be extended for urban
freight delivery. He has carried out a feasibility study on the underground
distribution of goods for the city of Leiden. If the Dutch parliament agrees to
provide further funds later this year, freight pipelines will receive a big
boost.

But none of today鈥檚 plans match the ambitious ideas of the engineers of an
earlier, more heroic age. In 1869, Alfred Beach built a pneumatic passenger
transport system in a 2.5-metre-diameter tunnel under Broadway in New York. It
boasted a station with a grand piano but functioned for only a few months. One
of its cars was retrieved in 1912 when workers building the current Broadway
subway broke into the old tunnel鈥擡d