Peak sound pressure

Since the value of Fg is not greater than 1, the exposure is within permissible limits. Also note that exposure to impulsive or impact noise should not exceed 140-dB peak sound-pressure level. 

A peak sound pressure of above 200 pascals or about 120dB is considered unacceptable and 130dB is the threshold of pain for humans. If a person has to shout to be understood at 2 metres, the background noise is about 85 dB. If the distance is oniy 1 metre, the noise level is about 90dB. Continuous noise at work causes deafness, makes people Irritable, affects concentration, causes fatigue and accident proneness, and may mask sounds which need to be heard in order to work efficientiy and safely. 

Impulse or impact noise 140 peak sound pressure level... 

The exposure criterion used in these Regulations is the equivalent noise level over the working day or shift (Lep ci). Three actions levels are identified, the first action level is an lEP,d of 85 dB(A) when an employee has to be provided with hearing protection on request (Reg. 8(1)), the second action level is an exposure of 90dB(A) or more when hearing protection must be provided and worn (Reg. 8(2)) and the third level is the peak action level when a peak sound pressure level of 200 pascals occurs when hearing protection must, again, be provided and worn. 

The source of noise and vibration on demolition sites will normally be caused by the use of plant and equipment, falling debris and/or explosives. Compressors, pneumatic hand-held tools, front end loaders, excavators and other equipment can create noise levels of more than the lower exposure action level of 80dB(A) and may at times create peak noise levels of more than 137 dB(C) the lower peak sound pressure action value. A noise assessment will be required and workers given ear defenders. 

---