Hearing ConservationPart Two – Hearing Protection Devices
An effective hearing conservation program can prevent hearing loss, improve employee morale and a general feeling of well-being, increase quality of production, and reduce the incidence of stress-related disease. The Occupational Safety and Health Administration (OSHA) recommend an employer should administer a continuing, effective hearing conservation program whenever employee noise exposures are at or above an eight hour time-weighted average (TWA) of 85 dBA. This is referred to as the action level.
An effective hearing conservation program consists of four parts – Part One – Monitoring Program; Part Two – Hearing Protection Devices; Part Three – Employee Training and Education; and Part Four – Recordkeeping. This Handout provides information on hearing protection devices.
The effectiveness of hearing protection is reduced greatly if the hearing protectors do not fit properly or if they are worn only part time during periods of noise exposure. To maintain their effectiveness, they should not be modified. Radio headsets are not substitutes for hearing protectors and should not be worn where hearing protectors are required to protect against exposure to noise. Other considerations include:
Hearing protection devices (HPDs) are considered the last option to control exposures to noise. HPDs are generally used during the necessary time it takes to implement engineering or administrative controls, or when such controls are not feasible.
Employers should make HPDs available to all employees exposed to noise at or above the action level. These must be provided at no cost to employees and must be replaced as necessary.
Employers should ensure that HPDs are worn by employees where feasible administrative and engineering controls fail to reduce sound levels and when employees are exposed to noise at or above the action level and who have not yet had a baseline audiogram established or have experienced a standard threshold shift (STS).
Employees should be given the opportunity to select their HPDs from a suitable variety. Generally, this should include a minimum of two devices, representative of at least two different types. The types of hearing protectors available include: (1) Ear plugs that block the ear canal, (2) Semi-insert ear plugs which consist of two ear plugs held over the ends of the ear canal by a rigid headband, or (3) Ear muffs that consist of sound-attenuating material and soft ear cushions that fit around the ear with hard outer cups and are held together by a head band.
The employer should provide training in the use and care of all HPDs provided to employees.
The employer should ensure proper initial fitting of HPDs and supervise their correct use.
The employer should evaluate HPD attenuation for the specific noise environments in which the HPD will be used. Attenuation refers to the damping or decrease of noise levels as a result of wearing HPDs.
HPDs should attenuate employee exposure to noise to at least an eight hour time-weighted average of 90 dBA.
For employees who have experienced a standard threshold shift (STS), HPDs must attenuate exposure to noise to a level at or below the action level of 85 dBA-TWA.
The adequacy of the HPDs should be re-evaluated whenever employee noise exposures increase to the extent that they may no longer provide adequate attenuation. The employer should provide more effective hearing protectors as necessary.
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