A simple definition of noise is: Any unwanted sound.
Noise is measured in decibels and the scale often employed dB(A)
is weighted to the range perceived by the human ear. The decibel
system is frequently misinterpreted as it is based on a logarithmic
scale. This means that a sound level of 100dB(A) contains twice the energy of a sound
level of 97dB(A).
A rise of 10 dB in sound level corresponds roughly to a doubling of
subjective loudness. Therefore a sound of 80 dB is twice as loud as a
sound of 70 dB which is twice as loud as a sound of 60 dB.
Correspondingly, the 80 dB sound is 4 times louder than the 60 dB sound.
Distance plays an important role in the perceived sound level. Sound
levels decrease by approximately 6 dB every time the distance from the
source is doubled.
A noise level of 35 to 40dB outside a dwelling is acceptable and a maximum
of 45dB should be adhered to in order to prevent disturbance to
Sound levels inside a property will be approximately 10dB less than
those outside, even when a window is open.
Noise not only affects hearing. It affects other parts of the body and
body systems. It is
now known that noise:
Increases blood pressure
Has negative cardiovascular effects such as changing the way the heart
Increases breathing rate
Can cause an upset stomach or ulcer
Can negatively impact a developing foetus and possibly contribute to
Makes it difficult to sleep, even after the noise stops
Intensifies the effects of factors such as drugs, alcohol, carbon
monoxide and ageing
In fact research now suggests that noise may be causing 2000-4000 deaths annually as a result of an increase in cardiovascular disease
Example Sound Levels
The threshold of human hearing (roughly the sound of a mosquito flying 3
||Leaves rustling / Calm breathing
||A quiet room / Whisper
||TV sound at home / Dishwasher
||Car at 10 metres / Vacuum cleaner
||Busy traffic at 10 metres / Alarm clock
Hearing damage (due to long-term exposure)
||Power tools / Lawnmower
||Pneumatic road drill at 1m / Chain saw /
Hearing damage (due to short-term
||Amplified music at 2m / Loud car stereo
Threshold of pain
||Jet taking off (100m away)
||Rifle being fired at 1 metre
||Jet engine at 30 m / Rock music peak
||Theoretical limit for a sound wave at 1
atmosphere environmental pressure
In order to prevent disturbance
to nearby residents, entertainment venues should fit one of the products
below to control sound levels from bands / DJs etc.
If you are experiencing noise problems you should first try talking to the person responsible. If you are not
comfortable doing this alone, your local council will put you in touch with a mediation service.
If the issue cannot be resolved by talking to the person responsible, the local authority environmental health department should be able to help.
It is a good idea to make a record of any disturbance you have suffered prior to contacting them. Include the following information:
The address where the noise comes from.
The type of noise - For example: Loud music, dogs barking.
When and for how long the noise occurs - keep a written record of the dates, times, duration and decibel level if possible.
The way the noise affects you - For example: Unable to sleep, Distracted from your work.
The products above can be used to keep a record of the actual noise level.
If you measure a level of over 35 decibels in an otherwise quiet room it could be considered as noise nuisance.