Hearing Conservation

High noise levels can damage hearing, especially if these levels are experienced over a long period of time. The Environmental Health and Safety Office provides noise level surveys on an as requested basis, and when determined to be needed based on observation and inspection. If you have a noisy area, please feel free to call us for assistance in determining whether the levels are too high. Some suspect activities include construction noise, use of heavy equipment, working in machine rooms, and certain operations, such as sanding, grinding, and jackhammer.

EHS has been contacted occasionally during construction activity outside which disturbs occupants of adjacent buildings. While these activities do not meet the OSHA criteria of excessive noise exposure, they can have an impact on the affected individuals. Any noise over normal background levels can interfere with speech, cause a stress reaction, lower morale, reduce efficiency, cause annoyance, interfere with concentration, and cause fatigue. Community noise levels in industrial areas are typically set at 61 dBA during the day. Administrators and managers should keep this in mind during periods of construction in adjacent areas.

A good source of information on noise and hearing conservation is the Occupational Noise Exposure webpage on the OSHA website.

The following information was extracted from LSU’s Safety Manual:

Standards

Time-weighted average (TWA) noise limits as a function of exposure duration are shown as follows:

Program Requirements for Occupational Noise Exposure

Noise

or unwanted sound, is one of the most pervasive occupational health problems. It is a by-product of many industrial processes. Sound consists of pressure changes in a medium (usually air), caused by vibration or turbulence. These pressure changes produce waves emanating away from the turbulent or vibrating source. Exposure to high levels of noise causes hearing loss and may cause other harmful health effects as well. The extent of damage depends primarily on the intensity of the noise and the duration of the exposure. Noise-induced hearing loss can be temporary or permanent. Temporary hearing loss results from short term exposures to noise, with normal hearing returning after a period of rest. Generally, prolonged exposure to high noise levels over a period of time gradually causes permanent damage. OSHA's hearing conservation program is designed to protect workers with significant occupational noise exposures from suffering material hearing impairment even if they are subject to such noise exposures over their entire working lifetimes. 

Monitoring

The hearing conservation program requires employers to monitor noise exposure levels in a manner that will accurately identify employees who are exposed to noise at or above 85 decibels (dB) averaged over 8 working hours, or an 8-hour time-weighted average (TWA.) That is, employers must monitor all employees whose noise exposure is equivalent to or greater than a noise exposure received in 8 hours where the noise level is constantly 85 dB. The exposure measurement must include all continuous, intermittent, and impulsive noise within an 80 dB to 130 dB range and must be taken during a typical work situation. This requirement is performance-oriented since it allows employers to choose the monitoring method that best suits each individual situation. Monitoring should be repeated when changes in production, process, or controls increase noise exposure. Such changes may mean that additional employees need to be monitored and/or their hearing protectors may no longer provide adequate attenuation.

Under this program, employees are entitled to observe monitoring procedures and they must be notified of the results of exposure monitoring. The method used to notify employees is left to the discretion of the employers.

Instruments used for monitoring employee exposures must be carefully checked or calibrated to ensure that the measurements are accurate. Calibration procedures are unique to specific instruments. Employers have the duty to ensure that the measuring instruments are properly calibrated. They may find it useful to follow the manufacturer's instruction to determine when and how extensively to calibrate.

NIOSH and other developers have Apps that can be downloaded on a personal phone to detect for noise levels. These apps are good screening tools; however, since they cannot be calibrated with reliability they do not replace more advanced meters. Additionally expertise in a noise investigation by a trained safety professional is needed to ensure the testing is being conducted in accordance with established methodology. 

Noise - Training Information

Supervisors and exposed workers must become aware of and understand about the adverse effects of noise and how to prevent noise-induced hearing loss. People exposed to hazardous noise must take positive action, if progressive permanent hearing loss is to be prevented. Each exposed worker and supervisor should know the following:

• Noise exposure may result in permanent damage to the auditory system and there is no medical or surgical treatment for this type of hearing loss. Though the use of a hearing aid may provide some benefit, normal hearing will not be restored. Many people don't realize loud sounds can cause hearing loss. Furthermore, in its initial stages, the person may not notice a problem since noise-induced hearing loss is invisible, painless, and occurs in the high frequencies. It is dangerous to ignore the temporary characteristics of noise-induced hearing loss (such as ringing or buzzing in the ears, excessive fatigue, etc.).
• Each person should know how to recognize hazardous noise even if a noise survey has not been conducted an/or warning signs posted. Recognizing and understanding the adverse effects of off-duty noise exposures is also important. The best rule to follow is: "If you have to shout at arms length (approximately three feet) to talk face-to-face, you are probably being exposed to hazardous levels of noise."
• Preventing noise-induced hearing loss is accomplished by reducing both the time and intensity of exposure. Reducing exposure time is accomplished by avoiding any unnecessary exposure to loud sound. Reducing intensity is usually accomplished by wearing personal hearing protection. Each person must be able to properly wear and care for the particular type of hearing protection selected. Speech communication is difficult in high intensity noise. However, most people don't realize it's easier to understand speech if hearing protection is worn in a hazardous noise environment. Hearing protection reduces the noise and the level of speech, resulting in a more favorable listening level. hearing protection reduces the intensity of frequencies above the speech range; thus, reducing the noise and accentuating speech. People who claim wearing hearing protection makes it difficult to hear speech are probably in noise levels less than 85 dBA or have already developed a hearing loss.
• Each person must know how to tell if they have been overexposed to loud sound. Overexposure may occur even while wearing hearing protection. Earplugs and/or earmuffs alone may not be enough protection. Each time a temporary threshold shift (TSS) occurs, a certain degree of permanent loss results. The recognizable symptoms of overexposure are described as "dullness in hearing or ringing in the ears."

General Program Management

Deans, Directors, Department Chairs, Principal Investigators, Managers and Supervisors are responsible for ensuring that noise hazards which may contribute to occupational hearing loss in there areas are evaluated.

Occupational & Environmental Safety is responsible for:

• Monitoring and evaluating noise sources upon request.
• Providing training for potentially noise exposed individuals upon request.

Workers responsibilities include the following:

• Learn about the potential hazards of noise exposure and follow the rules when around or operating noisy equipment.
• Wear or use prescribed protective equipment.
• Refrain from operating equipment without proper training or equipment that has safety defects.
• Attended training sessions for hazardous noise exposures.
• Be aware of the noise producing capabilities of equipment they are around or use.