Continuous noise is defined as noise whose highest levels occur more often than once per second.
Impulse , which is sharp outbursts of noise, such as that from pneumatic tools, use of explosives, impact tools, etc. Impulsive noise is assumed to have peaks occurring less often than once a second, and is limited to peak sound pressure levels of 140 dB. Both types of noise can be harmful, depending on how loud the noise is and how long you are exposed to the noise. Continued exposure to noise levels at or above 85 decibels will result in hearing loss and can impair job performance through employee irritability, fatigue and job stress. 115 Employee complaints about the loudness of noise Indications that employees are losing their hearing Noisy conditions that make conversation difficult Habitual exposure to noise above 85 dB will cause a gradual hearing loss in a significant number of individuals, and louder noises will accelerate this damage. For instance, exposure is limited to eight hours at 90 dB, four hours at 95 dB, and two hours at 100 dB. The highest permissible noise exposure for the unprotected ear is 115 dB for 15 minutes per day.