OSHA Guide to Noise and Hearing Safety, Health And Conservation

One of the occupational hazards of living in the modern industrial age is noise exposure, both in and away from the workplace. Acoustic noise can be defined as unwanted sound and sounds louder than 80 decibels (dB) are considered potentially dangerous. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), more than 30 million Americans are regularly exposed to hazardous sound levels. According to the EPA the number of people exposed to work induced noise damage is around 9 million.

Noise is considered a necessary evil and the insidious effects of exposure above acceptable levels are generally not realized, mostly because there are no visible effects. The primary effect of excessive noise is hearing loss, either temporary or permanent, depending on the level and duration of exposure. What is even less well known are the secondary effects ranging from sleep disturbances: stress and fatigue, irritability, annoyance and lack of concentration. Noise induced lack of attention and the consequent loss in efficiency are matters of prime concern in the workplace. Not only is productivity impaired, but chances of accidents, impinging on worker and workplace safety, are also increased.

The federal Occupational Safety and Health Administration (OSHA) has developed regulations for acceptable threshold limits of noise in the workplace and mitigation of excessive noise. The 29 CFR standards 1910.95 Occupational noise exposure, lays down permissible exposure limits for different durations of exposure. The recommend exposure level, as per the standard, is 85 dB A on an 8-hour time-weighted average (TWA) basis. If this limit is exceeded, feasible administrative or engineering controls are to be utilized. If such controls fail to reduce sound levels within the permissible exposure limits, personal protective equipment (PPE) is to be provided. Further, irrespective of the reduction of noise exposure to 85 dB A or below with the use of PPE, the employer is to implement a hearing loss protection program.

The 1910.95 standard refers to the mandated hearing protection program as the "Hearing conservation program". This program has five operational parts mandated: (1) Noise monitoring (2) Audiometric Testing (3) Employee Training (4) Hearing Protectors and (5) Record Keeping.

Noise monitoring
Sound levels in the workplace must be measured to ascertain which employees to include in the program, the need for hearing protection equipment and its suitability.

Audiometric Testing
All employees in the program must be subjected to a base line audiometric test to determine pre-existing hearing loss, if any. Annual tests are to be carried out thereafter to asses the effectiveness of the program and for appropriate remedial action as necessary. The standard specifically requires that the audiometric tests be carried out by duly qualified personnel under the supervision of an audiologist, otolaryngologist or physician.

Employee Training
All employees in the program must receive annual training on the effects of noise on hearing, hearing protection devices and the purpose of audiometric testing.

Hearing Protectors
Hearing protection devices must be made accessible to all employees in the program.

Record Keeping
Records of employee exposure (sound measurement), acoustic or exhaustive audiometer calibration, and audiometric test records must be updated. These records are to be maintained for specific periods of time.

Experience has shown that effective hearing loss protection programs are universally beneficial and that both employer and employees stand to gain from the programs. The employees are protected from hearing loss, fatigue and general debility. The employer benefits from improvement in employee morale and productivity and will also enjoy reduced medical and worker compensation costs.