This Loss Bulletin is intended to help municipalities reduce hearing loss in their employees. Well-trained employees who wear proper hearing protection need not suffer from occupational hearing loss. Presented here are Best Practice recommendations to monitor the noise level of municipal worksites and to regularly test and retest employees exposed to hearing loss.
Municipal employees who are exposed to loud noises such as sirens, heavy equipment, pumps, etc. may suffer noise-induced hearing loss. Occupational noise can cause hearing loss and increase the worker’s susceptibility to other workplace problems including physical and psychological disorders, interference with speech and communication and disruption of job performance associated with excessive noise intensities. This exposure to noise produces hearing loss of a neural type involving injury to the inner ear hair cells called cilia. Brief exposure causes a temporary loss. Repeated exposure to high noise levels will cause a permanent loss.
Permanent hearing loss is preventable with the continued use of proper hearing protection and reduction in workplace noise levels to below 85 decibels. This will benefit not only employees who can listen and communicate well throughout their lifetimes, but also helps the municipality in terms of reduced exposure to hearing loss workers’ compensation claims and a potential for increased general safety and job performance.
The Occupational Safety and Health Administration (OSHA) Occupational Noise Standard 29 CFR 1910.95 establishes a permissible exposure limit (PEL)for occupational noise exposure, and requirements for audiometric testing, hearing protection and employee training if noise sound levels are exceeded. This regulation defines an “action level” (AL) as a “dose” of 50%, which is equivalent to an eight-hour time weighted average of 85 decibels. When noise levels exceed this amount an effective hearing conservation program is required which includes as a minimum:
- Noise Monitoring
- Audiometric testing
- Audiometric evaluation
- Hearing protection
- Education and training
- Record keeping
Noise monitoring should be conducted whenever exposures are expected to be between 80 and 130 decibels. As a general rule of thumb, if conversation cannot be carried out between two people without shouting, noise levels should be monitored. Audiometric Testing
- Audiometric testing should be performed on all employees whose exposures equal or exceed 85 decibels.
- Audiometric testing should be provided at no cost to the employee.
- Audiometric testing should be performed by a certified or licensed audiologist, otolaryngologist, or other physician or by a technician who is certified by the Council of Accreditation in Occupational Hearing Conservation or who has satisfactorily demonstrated competence in administering audiometric examinations. A technician who performs audiometric tests must be responsible to an audiologist, otolaryngologist or physician.
- Baseline Audiogram
- A baseline audiogram should be conducted within 6 months of an employee’s first exposure to 85 decibels in order to establish a valid baseline audiogram against which subsequent audiograms can be compared
- Testing to establish a baseline audiogram should be preceded by at least 14 hours without exposure to occupational noise.
- Employees should also be advised of the need to avoid high levels of non-occupational noise exposure during the 14-hour period immediately preceding the audiometric examination.
- Audiograms should be conducted at least annually after obtaining the baseline audiogram for each employee exposed at or above an 8-hour time-weighted average of 85 decibels.
- The municipality should maintain a record of all employee audiometric test records. This record should include:
- Name and job title of the employee.
- Date of the audiogram
- The examiner’s name
- Date of the last acoustic or exhaustive calibration of the audiometer
- Employee’s most recent noise exposure assessment
- Each employee’s annual audiogram should be compared to their baseline audiogram by a qualified evaluator to determine if a Standard Threshold Shift (STS) has occurred.
- A Standard Threshold Shift is defined by OSHA as a change in hearing threshold relative to the baseline of an average 10 decibels or more at 2,000, 3,000, 4,000 Hertz in either ear.
- In determining if a STS has occurred, an allowance can be made for the contribution of aging (presbycusis). The age correction values to be used are found in Appendix F of CFR1910.95.
- If an annual audiogram indicates that an employee has incurred a STS, the person should be scheduled for a retest within 30 days to determine if the threshold shift is persistent.
- The following procedures should be followed if a comparison of the baseline audiogram indicates a persistent standard threshold shift:
- Employees not using hearing protectors should be trained,fitted and required to use hearing protection.
- Employees already using hearing protectors should be retrained, refitted and required to use hearing protection.
- The Safety Coordinator should inform the employee, in writing, within 21 days of the determination, of the existence of a permanent Standard Threshold Shift. A copy of the STS letter should also be sent to the employee’s supervisor.
- The Safety Coordinator should counsel the employee on the importance of wearing hearing protectors and refer the employee for further clinical evaluation if necessary. 6. Persistent significant threshold shifts must be entered on the Oklahoma Form 300 Log if determined to be work related.
- The Safety Coordinator should ensure that hearing protectors are worn:
- By any employee who is subjected to sound levels equal to or exceeding 90 decibels
- By any employee who has experienced a persistent Standard Threshold Shift and who is exposed to noise levels of 85 decibels or greater.
- By any employee who has not had an initial baseline audiogram and who is exposed to noise levels of 85 decibels or greater.
- Employees should be given the opportunity to select their hearing protectors from a variety of suitable hearing protectors at no cost to them.
- The Safety Coordinator should provide training in the use and care of all hearing protectors.
- The Safety Coordinator should ensure proper initial fitting and supervise the correct use of all hearing protectors.
- Employees should be held accountable for properly using and maintaining the equipment.
Education and Training
- An annual training program for affected employees should be conducted by the Safety Coordinator and should include information on:
- The effects of noise on hearing
- The purpose and use of hearing protectors
- The advantages and disadvantages of various types of protection
- Instruction in the selection, fitting, use and care of protectors
- The purpose of audiometric testing and an explanation of the test procedures
Noise exposure measurement records should be retained for at least two years. Audiometric test records should be retained for the duration of the affected workers employment plus thirty years. Occupational Hearing Loss is preventable! To do this, the municipality must make a commitment to monitor noise levels and baseline test and retest employees to determine that the hearing protection procedures are working.
Hearing Loss is Preventable was written by Gary Cauthen, OMAG Loss Control Specialist. You may contact the author at: firstname.lastname@example.org. The information in this bulletin is intended solely for general informational purposes and should not be construed as or used as a substitute for legal advice or legal opinion with respect to specific situations, since such advice requires an evaluation of precise factual circumstances by an attorney.