Hearing Conservation

Purpose and Scope

The OSHA Occupational Noise Exposure Standard, 29 CFR 1910.95, requires the establishment of a Hearing Conservation Program when employees are exposed to high noise levels in the workplace. Bates College Hearing Conservation Program is designed to protect employees from noise exposures that may cause permanent hearing damage. This program includes the following:

  • an ongoing program of monitoring, identification, and evaluation of noise hazards
  • a medical surveillance program which includes annual employees hearing test (audiogram) and appropriate follow-up for individuals who experience work related hearing loss
  • employee training on the effects of noise on hearing and the proper use and care of hearing protection
  • retention of noise monitoring, audiometric testing, and training records

Participation in the Hearing Conservation Program will be determined based on a noise hazard assessment. Employees participating in the Hearing Conversation Program will be required to wear hearing protection, as needed, to reduce noise exposure levels below 90 dBA TWA.

Employees who have experienced a standard threshold shift (STS) will have noise exposure levels attenuated below 85 dBA TWA. An STS is a permanent reduction in hearing at several hearing frequencies.


Noise, or unwanted sound, is one of the most pervasive occupational health problems in the workplace. Exposure to high levels of noise can cause hearing loss along with with other health effects.

Noise-induced hearing loss can be temporary or permanent.

  • Temporary: hearing loss the results from a short-term exposure to noise, with normal hearing returning after a period of non-exposure.
  • Permanent: prolonged exposure to high noise levels over a period of time gradually causes permanent damage.

The extent of the damage primarily on the intensity of the noise and the duration of the exposure.

Noise may be a problem in the workplace if you:

  • hear ringing or humming in your ears when you leave work.
  • have to shout to be heard by a coworker at one arm’s length away
  • experience temporary hearing loss when leaving work

Hearing Protection

The goal of Bates EHS is to protect employees from noise exposures that may cause hearing impairment. This may be accomplished through employee orientation on:

  • noise hazard areas and operations
  • availability and location of hearing protection devices
  • presence of warning signs indicating the need to wear hearing protection
  • location where hearing protection devices can be cleaned, if applicable

Supervisors may provide this information, will make hearing protection devices (HDP) accessible to employees, and ensure that HDP are used as required. In addition, noise hazard areas and equipment will be posted or affixed with “Hearing Protection Required” signs or labels.

Hearing Protection Devices (HDP)

Hearing protection devices are designed to insulate the human ear from noise hazards. They come in two primary forms:

  • Muffs: Acoustic muffs cover the ear with an insulated cup held in place by a band or suspension.
  • Plugs: Ear plugs are inserted into the ear canal to block noise from the inner ear.

HDP are required when working with loud equipment or in noise hazard areas at or above 90 dBA TWA and are recommended when exposed to greater than 85 dBA TWA.

Appropriate hearing protection must be provided to employees free of charge and made available when workplace exposures are at or greater than 85 dBA. A wide range of types and styles of acceptable HPD are available through various vendors.

Contact EHS for any recommendations regarding hearing protection.

Warning Signs

Noise hazard areas, greater than 90 dBA must be identified with area signage or equipment labels. Appropriate area warning signs and equipment stickers are available through EHS. Any modification in wording should be forwarded to EHS for recommendations.

Program Elements

Exposure Monitoring

Monitoring employee exposure to potential noise hazards is coordinated through Bates EHS. Employee noise exposure monitoring will be initiated:

  • through routine noise hazard awareness (surveys, inquiries, assessments, etc.)
  • when a change in an activity or process occurs that potentially increases the noise hazard to a level of 85 dBA or above
  • when a potential “noise” source is indicated on a Hazard Assessment

A calibrated sound level meter or noise dosimeter will be used to measure noise levels. If a potential noise hazard is identified in the initial monitoring using a sound level meter, a more detailed investigation may follow, where a noise dosimeter will monitor an employee’s noise exposure for an entire shift. Changes in time or equipment may require additional evaluation. Employees are allowed to observe the monitoring session and will be notified of it’s results.

If exposed to an action level of 85 dBA TWA or higher, the employee will be notified and included in the Hearing Conservation Program.

Impulsive or impact noise exposures above 140 dBA are not permissible of OSHA and hearing protection must be worn when exposed to these levels.

Medical Surveillance

Medical surveillance will consist of audiometric testing administered by a certified Occupational Medicine Office. This testing is available to employees at no cost and will be performed by a licensed professional or certified technician.

A baseline audiogram must be provided within six months of initial employment and an annual audiogram is required thereafter. Employees must be notified to avoid high noise levels for a minimum of 14 hours prior to the hearing examination.

The annual audiogram is evaluated to determine if an employee has experienced a standard threshold shift (STS). An STS is the reduction in hearing at several frequencies. If an STS is diagnosed, an employee will be notified of the hearing loss within 21 days and notified within 30 days if a retest is necessary. If further examination is necessary, hearing will be retested and pertinent information about noise exposures will be obtained from the employee.


Annual training is required for all employees in the Hearing Conversation Program. Training shall include:

  • effects of noise on hearing
  • correct use and purpose of hearing protection
  • information on the purpose of audiometric testing and an explanantion of the test procedures

Supervisors must provide site or job specific information and training to employees , in addition to training provided by Bates EHS. Site specific training must orient the worker to:

  • noise hazard and operations
  • availability and location of hearing protection devices
  • presence of any warning signs or labels indicating the need to wear hearing protection
  • location where hearing protection devices can be cleaned, if applicable


Recordkeeping is a require element of the Hearing Conservation Program. Records maintained by Bates include:

  • hazard assessments
  • exposure measurements
  • training
  • audiometric tests, and
  • measurements of background sound pressure levels in audiometric testing rooms

This information will be made to employees or representative upon request.

Records pertaining to the Hearing Conversation Program are categorized as follows:

  • Hazard Assessment: completed for employees exposed to loud noise sources. Assessments will be filed and maintained by Bates EHS.
  • Noise Exposure Records: filed and maintained by EHS.
  • Audiometric Test Records: filed and maintained by the Occupational Medicine Office.
  • Employee Training Records: filed and maintained by EHS.



Employees are responsible for completing a hazard assessment and ensuring they wear hearing protection devices (HDP) when required.


Supervisors are responsible for implementing the Hearing Conservation Program requirements in their departments. A supervisor must report to EHS any potential noise source hazards and ensure that employees wear their HPD when required. Training employees on their workplace noise hazards and providing HDP to employees are two other areas of supervisor responsibility.

Bates Environmental Health and Safety (EHS)

EHS is responsible for conducting exposure monitoring, notifying an employee and their supervisor of noise hazards, maintaining noise exposure records, and determining when Bates employees are included in the Hearing Conservation Program. EHS will maintain hazard assessments.

Occupational Medicine

Occupational Medicine is responsible for hearing examinations, training, and hearing-test record retention, and all aspects of audiometric testing.