SUBMITTED BY Fred Hill
August 13, 2001 — After a visit to JP3 a man thought about the sound level that he
was just a witness to, and wrote in a article to his local newspaper.
Maybe we should all think about this one. Thank you Squrik.
A VISIT to the cinema recently to watch the new blockbuster
movie Jurassic Park 3 prompted me to write this article.
The sound level in modern cinemas now has reached an unbearable
level and this is certain to cause damage to the ears of unsuspecting
cinemagoers.
This is not the only source of unbearable noise. Nowadays, the
younger generation likes to listen to exceptionally loud music with
increased high-distorted frequency range. This is often found at
parties, functions, discos and even music and computer game
shops.
If we do not check such a trend, I foresee half of the next
generation of grown-ups having hearing impairment. This will be a
national disaster. Nearly everyone will soon need to raise their
voice in order to be heard.
Selling hearing aids will become a very lucrative business in
Malaysia.
Health care providers should be concerned about this trend to
prevent future disaster. One important feature of noise-induced
hearing loss is that it is preventable in nearly every case except
those caused by accidents. It is however incurable.
We go to the movies to be entertained but nowadays a visit to
the cinema can also be unsettling for your ears. Some of the movies,
usually action and science fiction films, have sounds reaching
staggering heights.
It was reported that the film Godzilla released in 1998 reached
115dB. Star Wars: The Return of the Jedi reached 104dB.
Now the newer films have sounds of even higher magnitude. I am
sure the film Jurassic Park 3 must have a very much higher sound
level.
Someone who has watched the same film in Sydney and here told
me that the sound level in our cinema is very much higher.
The film industry apparently is aware of the problem but they
are not interested in reducing the sound for competitive reasons. One
top Hollywood producer has been quoted as saying: "I'm not going to
make a shuttle rocket launch too low. I'm going to make it so that
you feel it in your seat and in your gut". I guess he should have
added, "even at the expense of your health".
The Screen Advertising Association has stepped in to control
excessive loudness in cinema commercials. The association's new
maximum loudness level is 82dB as measured by the Dolby Model 737
loudness meter.
Loudness is measured in decibels (dB). For every 3dB increase,
the sound will be twice as loud. The sound intensity of an ordinary
conversation is usually less than 60dB. A loud shout may reach about
90dB.
A rock band typically plays music at the noise level of around
120dB which is the same amount of noise discharged from a large
aeroplane 30 metres away.
Discotheques in Malaysia apparently have noise sometimes
reaching over 140dB. Many people play their Walkman at noise levels
corresponding to 110dB. In a workplace, you must not be subjected to
110dB for more than 1 1/2 minutes without wearing ear protection. In
many countries noise level in the workplace must not exceed 85dB.
This level is an expression of how much noise we can take eight hours
a day.
Prolonged exposure to noise above 90dB gradually causes hearing
loss. One should not be exposed to noise of 100dB for more than 15
minutes. Exposure to noise more than 110dB for over one minute risks
permanent hearing loss.
Exposure to noise above 140dB can cause permanent damage even
after a few seconds of exposure. The eardrum will burst and cause
severe damage to the hearing apparatus when exposed to sound reaching
180dB as found in an explosion (such as discharging a firecracker
near the ear).
Dr Lee Yan San
Penang |
