A recent incident of noise pollution in our neighbourhood led me to do some research on this emotive issue.
My first stop was to read the Nelson Mandela Bay Metropolitan Municipality Noise Control By-Law on noise (http://www.mandelametro.gov.za/Documents.aspx?objID=85cmd=downloaddocID=648), which states:
Disturbing Noise: Means a noise level that exceeds the ambient sound level measured continuously at the same measuring point by 7 dBA or more.
Section 10(1): Subject to the provisions of sections 5 and 6(a), no person may operate or play a radio, television set, gramophone, recording device, drum, musical instrument, sound amplifier or similar device producing, reproducing or amplifying sound, or allow it to be operated or played, in a public place, if the noise level, measured at any point which may be occupied by a member of the public or at one metre from the source of the sound, exceeds 95dBA, unless permission has been obtained from the municipality.
Please note – nowhere in the by-law is ANY mention made that you may make a noise until 10:00 pm OR that you have to be warned three times – the standard is that if a noise exceeds the normal ambient noise level by 7dBA or more then it is a nuisance.
Some further research by myself reveals some interesting information. Most international noise control bodies say that permission given to people who will be producing disturbing noise levels should limit those levels to below 85 Decibels.
Some regulatory authorities also insist on warning signs to be posted prominently at the entrance to events and all provide guidelines in terms of noise levels.
Many regulatory bodies make reference to the Cost of Noise (see further down) which can lead to people affected making stupid brain dead mistakes and not concentrating at all. Noise also leads to people losing productive days whilst waiting for body clocks to catch up.
Below I have posted excerpts and links to different publications concerned with noise:
The department of public works recommends the following with regards to workplace noise:
Tasks identified where noise levels exceeds 85 dB at any one time.
All reasonable steps taken to reduce noise levels at the source.
Hearing protection used where noise levels could not be reduced to below 85 dB.
The Cost of Noise
Economic interest has always dominated noise control, but we now have to weigh this against other likely costs such as: –
- Loss of earnings
- Loss of productivity
- Burden on the health services and the criminal justice system
- Increasing violence
- Human misery
- Social anger
- Loss of quality of life that noise causes.
Myths about Noise
- “You can get used to it” – You never do, even while asleep, your body reacts to it as a warning signal.
- “It’s my right to make a noise” – Noise hurts and you have no right to hurt others.
- “Noise has to be loud to be annoying” – A dripping tap or the dull “thump thump” of amplified music can cause extreme stress.
Disturbing Noise – Means a noise level that exceeds the ambient sound level measured continuously at the same measuring point by 7 dBA or more.
A person shall not, in an enclosed space, operate or play a radio, television set, gramophone, recording device, drum, musical instrument, sound amplifier or a similar device producing, reproducing or amplifying sound, or allow it to be operated or played, in a public place, if the equivalent continuous rating level (LReq,T), measured in accordance with SANS 10103—
(a) exceeds 95 dBA if measured at any point which may be occupied by a member of the public for longer than one (1) hour continuously;
(b) exceeds 85 dBA if measured at any point which may be occupied by a member of the public for a continuous period of eight (8) hours or more, unless permission has been obtained in writing prior to the event from the local authority having jurisdiction.
Sound has both frequency and intensity. Frequency or pitch, is measured as sound vibrations per second, or hertz (Hz). The frequency of a boat whistle or a locomotive horn is approximately 250 Hz, while the frequency of a bird singing or a cable saw is about 4 000 Hz. Intensity, or loudness, is measured in decibels (dBA). A conversational voice is around 65 dBA; a shout is 90 dBA or greater.
Decibels are an indicator of a sound’s loudness (measured by how much pressure sound exerts on a surface). As the decibel level rises, the sound increases more rapidly than you perceive it. A sound of 90 dBA is 10 times stronger than a sound of 80 dBA. A sound of 100 dBA is 100 times stronger than a sound of 80 dBA.
Continuous exposure to noise (85 dBA or greater) can cause permanent loss of hearing. Short exposure to extremely loud noise (greater than 140 dBA), known as acoustic trauma, can also cause permanent hearing loss.
For the protection of public health, the Environmental Protection Agency proposed these levels:
- Neighborhoods – During waking hours 55 dB
- Neighborhoods – During sleeping hours 45 dB
- Classrooms – during teaching sessions 35 dB
- Hospitals – during waking hours 45 dB
- Hospitals – during sleeping hours 35 dB
For the workplace, the Occupational Safety and Health Administration (OSHA) proposed these permissible noise exposure times:
- 85 dB and higher – prolonged exposure will result in hearing loss
- 90 dBA – no more than 8 hours per day (examples – lawn mower, truck traffic, hair dryer)
- 95 dBA – no more than 4 hours per day
- 100 dBA – no more than 2 hours per day (example – chain saw)
- 105 dBA – no more than 1 hour per day
- 110 dBA – no more than ½ hour per day
- 115 dBA – no more than ¼ hour per day (preferably less)
- 140 dBA – NO EXPOSURE TO IMPACT OR IMPULSE NOISE ABOVE THIS LEVEL (examples – gunshot blast, jet plane at takeoff)
The Academy of Pediatrics and the National Campaign for Hearing Health states 85 dB is the threshold for dangerous levels of noise.
The National Campaign for Hearing Health’s Toxic Noise Guidelines (exposure times and decibel levels that cause hearing loss)
- 85 dB 8-hour period
- 85 – 90 dB 2-hour period
- 90 – 100 dB 1 to 2-hour period
- 100 – 110 between 2 and 15 minutes
- 110 – 120 less than 30 seconds
- 130 dB ANY EXPOSURE WILL RESULT IN PERMANENT HEARING LOSS
RECOMMENDED LEVELS: The more often and the louder you player your player, the more likely you’ll experience some hearing loss. To come up with recommended listening times and sound levels, the researchers compared the players’ volume levels to the minimum sound level for the risk of hearing damage: 85 dBA. Typically, a person can tolerate about two hours of 91 dBA per day before risking hearing loss. The researchers recommend listening to iPods for — hours a day with earphones if the volume is at 80% of maximum levels. Listening at full volume is not recommended for more than 5 minutes per day using the earphones that come with the player.
OUTDOOR CONCERT NOISE – ENVIRONMENT PROTECTION POLICY
A number of factors contribute to the degree of adverse impact on residential areas from noise emitted during outdoor concert events:
- the level and nature of the noise;
- the number of events each year;
- the time at which the event takes place;
- the spread of events during the year; and
- the amount of warning (“prior notification”) provided to residents about upcoming events.
The EMA will not authorise an event that is likely to produce noise which exceeds 65 dB(A) (L A10 T) at the compliance location for 15 minutes or longer.
OSHA Daily Permissible Noise Level Exposure
Hours per day – Sound level
- 8 – 90dB
- 6 – 92dB
- 4 – 95dB
- 3 – 97dB
- 2 – 100dB
- 1.5 – 102dB
- 1 – 105dB
- .5 – 110dB
- .25 or less – 115dB
NIOSH Daily Permissible Noise Level Exposure
Hours per day – Sound level
- 8 – 85dBA
- 6 – 86dBA
- 4 – 88dBA
- 3 – 89dBA
- 2 – 90dBA
- 1.5 – 92dBA
- 1 – 94dBA
- .5 – 97dBA
- .25 or less – 100dBA
- 0 – 112dBA
Perceptions of Increases in Decibel Level
- Imperceptible Change – 1dB
- Barely Perceptible Change – 3dB
- Clearly Noticeable Change – 5dB
- About Twice as Loud – 10dB
- About Four Times as Loud – 20dB
http://www.gcaudio.com/resources/howtos/loudness.html – a comprehensive page containing many links to other sources.
NOTE: If you feel that your rights have been trampled on by a neighbour with regards to noise pollution you may report it to: Assistant Director: Air Pollution and Noise Control, Mr Titima – titima[at]mandelametro.gov.za