Hearing Conservation

Effects of noise• Causes hearing loss

• Amount of damage depends upon the intensity of the noise and duration of exposure

• Noise-induced hearing loss can be temporary or permanent

1a

Effects of noise• Prolonged exposure generally causes

permanent damage

• Noise-induced permanent threshold shift is not reversible/cannot be medically treated

1b

Effects of noise• Noise-induced hearing loss typically

starts with hearing threshold shifts in the higher frequencies

• The type of hearing loss can be identified and measured with audiometric examination

1c

Noise hazards• Noise is unwanted/unpleasant sound

that may have a negative effect depending on:– loudness/frequency– duration of exposure– how old/healthy

person is

2a

Noise hazards• Sound is measured by:

– frequency– intensity

• Noise types include:– wide band– narrow band– impulse

2b

Noise hazards

• Hearing protection must be provided when noise equals or exceeds an eight-hour time-weighted average of 85dB

2c

Noise hazards can cause:• Drowsiness and irritability

• Inability to hear important instructions

• High blood pressure, ulcers, headaches

2d

Noise hazards can cause:

• Sleeping disorders

• Temporary or permanent hearing loss

2e

Control measures• Isolate noisy machinery in a separate

area

• Place machinery on rubber mountings

• Use sound-absorbing acoustical tiles

3a

Control measures• Arrange work schedules to reduce

employee exposure to noise

• Inform supervisors of unpleasant/unacceptable noise levels

3b

Hearing protection• Factors taken into account when

selecting hearing protection devices include:– noise hazards– noise frequencies– fit and comfort– noise reduction – rating

4a

Purpose/procedure for audiometric testing

• Checks a person’s hearing

• Trained technician uses an audiometer to send sounds through headphones

5a

Purpose/procedure for audiometric testing

• Person being tested responds to the sounds when they are first heard

• Chart records responses

5b

Hearing protection makes common sense

• You are ultimately responsible for your own hearing

• You have the most to lose if you suffer hearing loss

• Make sure earplugs fit properly

6a

Hearing protection makes common sense

• Have an annual hearing test

• Keep hearing protection devices in good operation

6b

Hearing protection makes common sense

• Don’t use homemade hearing protection devices

• Wear hearing protection devices at work as required

6c