Hearing Protection

If noise levels in your lab exceed 85 dB, engineering or administrative controls are required to reduce the risk of occupational noise-induced hearing loss. If you think your lab has harmful noise levels (e.g. if it is difficult to carry on a conversation), contact the Safety Office at ext 33587 for an assessment. The Safety Office will do sound measurements and recommend the method and amount of attenuation required and the available types of hearing protection.

The measurement system for noise is expressed in decibels (dB). The decibel scale is logarithmic (ie 93 decibels are twice as loud as 90 decibels). There are 3 different scales for measuring sounds the scale most commonly used to measure noise exposure that may harm human hearing is the A scale. Therefore, noise levels are described on the A scale as dBA.

Typical Noise Levels

SOUND SOURCE

Lowest limit of hearing
Rustling leaf
Quiet farm setting
Whisper
Dripping faucet
Low conversation
Ordinary conversation
Idling car
Silenced compressor
Backhoe
Unsilenced compressor
Rock drill
Pile driver*
Rivet gun*
Explosive-actuated tool*

^{*Intermittent
or "impulse" sound}

DECIBEL (dBA)

0
10
20
20
40
50
60
70
80
80
100
110
120
130
140

Types of Hearing Protectors

DISPOSABLE EARPLUGS

PERMANENT EARPLUGS

EARMUFFS

Selection of Hearing Protection

The Safety Office will do sound measurement and recommend the amount of attenuation required and the available types of hearing protection.