Bruel & Kjaer experiment shows noise as a health hazard
A shouting contest, held by Merstham Beaver Cubs group, proved noisier than expected with one young member’s yell measuring louder than a jumbo jet. The contest, organised by the club leaders to celebrate Noise Action Week (running 19th to 23rd May), took place at the Merstham Beaver’s ‘tin’ Nissan hut in Battlebridge Lane, Surrey.
Using a sound level meter and microphone to record the results, the 24 Beavers took turns in making their loudest noise. Despite some ear splitting noises, they failed to tip the sound level meter until 7-year old Theo Harrison won the competition with his massive 137 decibels shout, which is 7 decibels higher than the threshold of pain and 17 decibels louder than the front row of a rock concert.
A collective shout from all the other members couldn’t even beat Theo’s result. “'The Beaver Hut was very reverberant and this coupled with very excited kids made for some very high and impressive measurements,” said John Gregory, a Technical Engineer from noise monitoring specialist Bruel &, Kjaer UK, whom supplied the sound level meter. “When the kids were playing the game we got an LAmax of 105dBA, so I believe you could make a case for some sort of hearing protection for the Cubs leaders.”
“We’re well aware that noise inside the meeting hut is terrible and do our best to organise outdoor activities,” commented Beaver Cubs Leader, Jack Pease. “In space, no one can hear you scream’ is a very apt phrase. We often go home from a pack evening with a headache, an hour is about as much one can stand.” After deafening themselves in the interest of science, the Beavers then learned how to communicate quietly – deaf signers from Merstham came in to demonstrate that not all communication need be loud.
In stark contrast to the ear-splitting cacophony of the first part of the evening, the Beavers learned to ‘talk’ to each other in total silence. By the end of the evening they were able to tell each other their name, say hello and say how old they were. Noise Action Week is held every year to highlight the dangers of excess noise.
At best too much noise is annoying, at worst it can be a legal nuisance or even a health hazard. Recent studies have shown that 3% of heart attacks have been brought on by increased stress as a result of too much noise. In a number of high profile cases, neighbourhood disputes caused by noise nuisance have led to violence and even killings.