Noise level

Noise can be defined as undesired sound, or sound which causes disturbance or annoyance to the recipient. One scientific measure of noise levels is the decibel (dB), which is calculated according to a logarithmic intensity scale.

Noise levels between 120 dB and 150 dB (e.g., airplanes taking off and landing, drilling and sawing of roadways) are dangerous to human hearing. 'Pleasant' noise levels are between 30 dB and 50 dB, though these levels are sometimes unachievable in today's society.

The Government has defined three noise levels:

• No observed effect level – the level of noise exposure where there is no effect on health or the quality of life.
• Lowest observed effect level – adverse effects on health and the quality of life can be detected.
• Significant observed adverse effect level – the level of noise exposure where there can be significant effects on health and quality of life.

In Great Britain, over one million employees are exposed to noise levels at their workplace which pose a risk to their hearing.

In April 2006, the Control of Noise at Work Regulations 2005 came into force, replacing the Noise at Work Regulations 1989. The regulations were established under the Health and Safety at Work etc. Act 1974 and implemented the European Council directive 2003/10/EC. The regulations require that employers protect their employees from noise levels that could cause hearing damage.

[edit] Related articles on Designing Buildings

• Acoustics in the workplace.
• BREEAM Reduction of Noise Pollution.
• Control of Noise at Work Regulations 2005.
• Decibel dB.
• Noise at Work Assessment.
• Noise nuisance.
• Sound insulation testing.
• Workplace noise exposure estimator.