Hearing Conservation Exam 2

How do you calculate barrier height?

You take the speed of sound divided by frequency, then multiply by 5

What is the speed of sound?

1128 ft per second

What does CAOHC stand for?

Council for Accreditation in Occupational Hearing Conservation

What does TTS stand for?

Temporary threshold shift

What does OSHA stand for?

Occupational Safety and Health Administration

What does ANSI stand for?

American National Standards Institute

What does STS stand for?

Standard Threshold Shift

What does NRR stand for?

Noise Reduction Ratio

What does NIPTS stand for?

Noise Induced Permanent Threshold Shift

What frequencies do we use to calculate pure tone average for finding monaural hearing impairment percentage?

500, 1000, 2000, and 3000

What frequencies do we use to determine a standard threshold shift?

2000, 3000, and 4000

How do you become CAOHC certified?

It’s a 20 hour course with at least 3 specialists

Renewed every 5 years

What are 5 types of hearing protection?

1. Earmuffs

2. Earplugs

3. Premolded

4. Formable plugs

5. Custom plugs

What are 2 advantages and 2 disadvantages of earmuffs?

1. One size - easy to dispense

2. Good for intermittent exposures

1. Bad reports on long term wear (tight, hot, bulky, heavy)

2. Bad for eye glasses

What are 2 advantages and 2 disadvantages of earplugs?

1. More comfortable for warm environments

2. Can be worn with other safety equipment

1. Difficult to monitor use

2. Requires more skill and attention

What is a pro and con of premolded?

Pro: Available with attached cords

Con: can become uncomfortable

What is a pro and con of formable plugs?

Pro: Comfortable and user accepted

Con: Bad when frequent insertion is necessary

What is a pro and con of custom plugs?

Pro: custom fit for each person

Con: Can have poor attenuation due to inaccurate ear impressions

What is a type 1 audiometer?

A full diagnostic audiometer designed for comprehensive hearing assessments

What is a type 2 audiometer?

A diagnostic audiometer with slightly fewer features, but still capable of basic diagnostic testing.

What happens if a patient has a standard threshold shift?

• Retest within 30 days

• Written notice to patient within 21 days

• Document in log

• Bring patient down to at least 85 dB TWA

• Reinstruct how to put in hearing protection