Hearing Protection

Course Objectives

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• Hearing Program Requirements
• The Importance of Training
• Program Implementation
• Program Key Elements
• Principles of Hearing
• Types of Hearing Devices
• Inspection of Hearing Devices
• Maintenance of Hearing Devices

Program Requirements

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• Establish a Written Program
• Conduct Audiometric Testing
• Address Noise Exposure Standards
• Conduct Regular Program Evaluations
• Conduct Work Area Noise Surveillance
• Conduct Hearing Conservation Training
• Control Hazards Using Ear Protectors as a Last Resort
• Ensure Proper Selection of Noise Exposure Equipment

Importance of Training

• Reduce injury and illness rates
• Workers feel better about their work
• Reduce workers compensation costs
• Elevate HSE compliance to a higher level

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A GOOD PROGRAM WILL HELP:

Program Implementation

• Establish responsibility.
• Establish a corporate policy and develop rules.
• Conduct a noise survey of the facility.
• Determine appropriate noise control measures.
• Eliminate noise hazards where possible.
• Conduct employee training.
• Provide protection where hazard elimination is not possible.
• Perform inspections and maintenance.
• Periodically audit the program.
• Modify policies and rules as appropriate.

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DEVELOPMENT SEQUENCE:

Program Implementation

The initial goal should be to reduce or eliminate noise hazards by:

1. Elimination or substitution of noise

producing sources.

2. Insulating equipment to lower noise

levels.

3. Implementation of administrative

controls.

4. Implementation of engineering

controls.

5. Issuance of hearing protection

equipment.

6. Providing training and procedures.

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DEVELOPMENT SEQUENCE:

Continued

Recognition

ASSESSMENT OF NOISE HAZARDS:

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• Known jobs/areas having high noise sources.
• Known jobs/areas requiring noise protection.
• Jobs/areas having had recent operational changes.
• Jobs/areas with new equipment or processes.
• New jobs having little or no statistical injury data.

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Continued

Evaluation

• Facility audit data.
• Employee surveys.
• Accident investigations.
• Industrial Hygiene surveys.
• Logs of employee complaints.
• Organizational structure development.
• Statistical evidence of known/potential hazards.
• Injury and illness data of known/potential hazards.

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Implementation

• Written program.
• Training program.
• Employee involvement.
• Supervisor involvement.
• Corrective action program.
• Job hazard analysis program.
• Organizational structure establishment.
• Safety in purchasing (new equipment, products etc.)

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Control

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• Periodic facility audits.
• Written program reviews.
• Industrial Hygiene surveys.
• Employee feedback surveys.
• Job hazard analysis reviews.
• Recurrent training programs.
• Supervisor feedback surveys.
• Periodic statistical evaluations.
• Corrective action follow-up measures.

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Continued

Control

• CONTROL MEASURES CONSIDERATIONS:

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• Capital improvement plan to eliminated hazards.
• Costs involved in implementing control measures.
• Length of time necessary for implementation.
• Level of urgency in implementation.
• Compatibility with existing controls.
• Cost of hearing protection equipment.
• Anticipated problems with employee use.

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Prioritization

• PRIORITIZATION CONSIDERATIONS:

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• Severity of injuries as a result of hazards.
• Consequences of an injury at the worksite.
• Likelihood that the operation will have an injury.
• The length of exposure to the hazard.
• Long-term effects of noise exposure.

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Program Key Elements

1. Noise Exposure Monitoring

2. Engineering and Administrative Controls

3. Use of Hearing Protection Devices

4. Training and Motivation

5. Program Review and Evaluation

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KEY PROGRAM ELEMENTS INCLUDE:

Key Program Elements

• NOISE EXPOSURE MONITORING
• Define Survey Goals
• Characterize the Hazard

Accurately

- Area Surveys

- Noise Dosimetry

- Engineering Surveys

• Ensure Results are

Representative

• Identify Affected Employees
• Evaluate Specific Noise Sources
• Prioritize Noise Control Efforts

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Key Program Elements

• ENGINEERING AND ADMINISTRATIVE

CONTROLS

• Reducing Reverberation and Echo's
• Reducing Structure-borne Vibrations
• Initiate Physical Changes at the Noise Source
• Modify or Replace of Equipment
• Physical Changes in the Transmission Path
• Examples Include:

- Sound Absorbing Material

- Mufflers on Noise Sources

- Acoustical Enclosures and Barriers

- Vibration Mounts and Proper Lubrication

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Key Program Elements

Use of Hearing Protection Devices

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• Ear Muffs (Circum-aural)

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• Semi-Inserts (Semi-Aural)

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• Inserts (Aural)

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Each type has advantages and disadvantages

Training and Motivation

• Job-specific training is essential
• Annual recurrent training recommended
• Active employee participation is essential
• Training is essential to employee motivation
• Training needed for:

- Managers

- Supervisors

- Affected employees

- Maintenance personnel

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Program Review and Evaluation

• Noise surveys (area and personal)
• Job hazard analysis assessments.
• Employee surveys.
• Review of results of facility evaluations.
• Analysis of trends in injury/illness rates.
• Up-to-date records of logs of noise hazard improvements tried or implemented.
• Before and after surveys/evaluations of job/worksite noise protection changes.

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EVALUATION TECHNIQUES INCLUDE:

Written Program

• WRITTEN PROGRAMS MUST BE:

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• DEVELOPED
• IMPLEMENTED
• CONTROLLED
• JOB SPECIFIC
• UNDERSTANDABLE
• SUFFICIENTLY DETAILED
• PERIODICALLY REVIEWED

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Principle of Hearing

• NOISE MEASUREMENT
• Decibel (dB)

- A unit of measurement for sound pressure

• 85 Decibels (dB) is max for the average workday
• 140 Decibels (dB) is max for impulse or impact noise

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Continued

No exposures in excess of 140dB peak sound pressure level are permitted. Impulsive or impact noise is considered to be those variations in noise levels at intervals of greater than one per second. Where the intervals are less than one second, it should be considered continuous. Source: ACGIH

Principle of Hearing

• NOISE MEASUREMENT

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Continued

• Sound is measured in two ways:

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1. Frequency

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2. Intensity

Principles of Hearing

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FREQUENCY: The pitch -- how high or low the sound is. Expressed in cycles per second (CPS). Most people can hear pitches between 20 CPS and 20,000 CPS.

Principles of Hearing

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Continued

INTENSITY: The loudness of sound. Expressed in units called decibels (dB). the more dB’s, the louder the sound. One decibel in the smallest unit of sound a person can hear.

Principles of Hearing

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NOISE REDUCTION RATING (NRR): A single number measure of the amount of attenuation of sound that a hearing protection device will reduce outside sound to. Expressed in units of decibels (dB).

85dB

45dB

NRR 40dB

Principles of Hearing

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The TLV is the upper limit of noise as measured in decibels averaged over an eight hour work day to which an average healthy person may be repeatedly exposed on an all-day, everyday basis without suffering adverse hearing loss.

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American Conference of Governmental Industrial Hygienist (ACGIH).

THRESHOLD LIMIT VALUE

Principles of Hearing

• THRESHOLD SHIFT

Hearing loss caused from noise can raise your

Hearing-threshold?-- the degree of loudness at

which you first begin to hear sound. Two types of

shifts can occur:

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1. Temporary threshold shift

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2. Permanent threshold shift

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Principles of Hearing

• TEMPORARY THRESHOLD SHIFT
• Most of the loss occurs in

the first two hours

• Workers may not hear

sound under 40db after

work

• Hearing returns within two

hours after exposure stops

• The loss can become

permanent with long exposure

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Principles of Hearing

• PERMANENT THRESHOLD

SHIFT

• Usually no physical signs
• Early signs may be tinnitus,

ringing, muffling of sound

• Hearing no longer returns

within two hours

• The loss starts in high

frequencies and may spread

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Continued

Principles of Hearing

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WORK SOURCES & FACTORS AFFECTING HEARING:

• Age
• Pitch
• Loudness
• Surroundings
• Type of machines
• Position of source
• Length of exposure
• Previous ear trouble
• Distance from source
• Think about your personal work habits!

Principles of Hearing

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HOW LOUD IS LOUD?

Continued

Principles of Hearing

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Continued

HOW LOUD IS LOUD?

Principles of Hearing

• EXTREMELY HIGH, LOUD NOISE
• Can cause traumatic Hearing Loss

- May be caused by a single exposure to loud

noise

- Less common than other types of hearing

damage

• Can cause other effects in the work place

- Contributes to poor communication at work

- Unpleasant sound may cause fear, anger etc.

- Noise may cause fatigue or distractions

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Continued

Principles of Hearing

• WHEN IS NOISE TOO LOUD?
• You have to raise your voice to be heard.
• You can’t hear someone less than 2 feet away

from you.

• Speech sounds muffled after you leave a noisy

area.

• You have ringing in your ears after exposure to

noise.

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Hearing Devices

• EAR MUFFS (CIRCUMAURAL)
• Surround the ear to reduce sound
• Very effective at reducing sound
• One size usually fits everyone
• Can be expensive
• Cleaning can be time-consuming
• Bulk can be a problem
• Can be uncomfortable in hot

conditions

• Can be attached to:

- Helmets

- Bump caps

- Hard hats

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Continued

Hearing Devices

• SEMI-INSERTS (SEMI-AURAL)
• Insert partially into the ear
• Snug fit is essential
• Moderately effective at

reducing sound

• Do not always effectively seal

ear canal

• One size fits all
• Large variety of shapes
• Cleaning is simple
• Bulk is not a problem
• Comfortable in hot conditions

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Hearing Devices

• INSERTS (AURAL)
• Training is essential to proper

use

• Insert into the ear
• Snug fit is essential
• Moderately effective at

reducing sound

• Do not always effectively seal

ear canal

• Large variety of shapes
• Cleaning is simple
• Bulk is not a problem
• Comfortable in hot conditions

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Continued

Hearing Devices

INSERTS (Available in three forms)

• Pre-molded Inserts - which may be universal-fitted or sized.

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• Custom Molded Inserts - which are either fabricated at a factory from an impression

taken of the ear canal or designed so that the impression itself becomes the final device.

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• User Molded Inserts - which may be reusable or disposable, expand in the ear canal to form a seal after they are rolled and inserted.

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Continued

Hearing Devices

• SELECTION CONSIDERATIONS
• Will they effectively reduce

sound levels?

• Comfort - will the users wear

them?

• Cost
• Ease of use and repair
• Sizing and fitting ranges
• Dielectric considerations
• Training and skill for use
• Durability and life expectancy
• Anthropometric considerations
• Availability of replacement parts
• Size, weight, pressure,

adjustability

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Inspection of Hearing Devices

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• Do a fit test to ensure proper seal.
• Receive proper training in its use.
• Provide proper care for equipment.
• Ensure hazard levels are known.
• Review noise exposure limits.
• Receive annual and recurrent training.
• Select correct hearing protection devices.

HEARING DEVICE CHECKLIST:

• Follow local policies and procedures.
• Wear only approved hearing protection devices.
• Wear only devices on which you have received training.

Maintenance of Hearing Devices

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• Read the manufactures guidelines first!
• Disassemble (if needed) in accordance with procedures.
• Scrub devices in detergent and warm water.
• Rinse to remove detergent.
• Air-dry, do not dry rubber under heat or sunlight.
• Never use solvents to clean plastic or rubber.

CLEANING AND DISINFECTING CONSIDERATIONS:

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• Protect from sunlight, heat, cold, moisture and chemicals!
• Place devices in individual sealable plastic bags

STORAGE CONSIDERATIONS:

Summary

Success is no accident. Never forget about safety ... Hear to-day gone tomorrow - use you hearing protection ...�

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