Hearing Protection Program

Tags SOP Safety

Purpose

This Standard Operating Procedure (SOP) outlines the standardized processes and procedures to be followed within The College of St. Scholastica for hearing conservation and noise exposure reduction. Adhering to this SOP ensures safety, consistency, efficiency, and quality in our operations.

Scope

This SOP applies to all The College of St. Scholastica employees involved in activities or areas where noise levels may exceed the Occupational Health and Safety Administration (OSHA) action level of 85 dBA.

Responsibilities

  1. Occupational Safety, Health, and Emergency Management Director: Responsible for overseeing the implementation of this SOP, conducting noise monitoring, scheduling or conducting baseline and ongoing hearing tests, recommending noise reduction methods, and providing training.
  2. Supervisors, Managers, and Department Heads: Responsible for ensuring that employees and students are following this SOP. Supervisors must ensure employees have access to and are using hearing protection when necessary.
  3. Employees and Students: Responsible for following this SOP, using hearing protection when necessary, and reporting any concerns about noise exposure.
  4. Human Resources: Responsible for maintaining hearing test records.

Procedures

Background Information

  1. Workplace noise can cause hearing loss, create physical and psychological stress, and contribute to accidents by making communication difficult. 
  2. Definitive evidence exists that the high noise level in a workplace can damage hearing, resulting in irreversible hearing loss. This hearing loss is referred to as Noise Induced Hearing Loss (NIHL). Initially, NIHL affects a person’s ability to hear sounds in higher frequency ranges of 4,000 to 6,000 Hz. If the exposure continues, deterioration in the lower frequency range will eventually occur. 
  3. The severity of hearing loss or the length of time before hearing loss is noticeable or measurable directly relates to the intensity of the noise, and the duration of exposure to high noise levels. 
  4. Since NIHL is a painless and gradual process, the sufferer is usually unaware of the problem until the hearing loss is severe. Generally, family members and friends are aware of the problem before the victim of the NIHL is. The affected person may seem to be ignoring them, unresponsive, or distant. 
  5. Noise becomes hazardous when a person is exposed to an average noise level of 90 dBA or more over an either-hour shift. Therefore, OSHA has stipulated that the employer shall implement controls to limit employees’ average noise level exposure to less than 90 dBA. 
  6. Some portion of the population may suffer hearing loss at an average noise level of 85dBA. OSHA has specified an action level of 85 dBA in the standard, meaning employers must provide hearing protection starting at exposure levels of 85 dBA (this average does not include any reduction from personal protective equipment). 
  7. A hearing conservation program protects The College’s most valuable resource - its employees. 

Plan Review

  1. This plan must be reviewed annually to ensure compliance and updated as needed.

Noise Level Testing

  1. The workplace must be surveyed to determine if:
    • Noise levels are known to be above 85 dBA
    • Employees complain about noise levels
    • Employees suspect work related hearing loss
    • Normal conversation is difficult due to noise levels
    • Equipment information indicates that high noise levels are produced.
  2. Noise levels must be re-tested any time there is a change to process, equipment, or controls in the area. 
  3. Noise testing will be tested using a noise dosimeter that attaches to the worker’s shirt collar and integrates noise levels from 80-130 dB over an 8 hour workday. 
    • All continuous, intermittent, and impulse noise levels from 80-130dB will be integrated into the reported results.
    • Testing equipment must be calibrated before and after use according to the manufacturer’s instructions to ensure accuracy and precision of results.
  4. Employees who are tested must be given the opportunity to review the testing results.
  5. If noise testing results are equal to or greater than 85dBA for the 8-hour TWA employees will need to have audiometric testing conducted and instructed  

Audiometric (Hearing) Testing

  1. No locations at The College of St. Scholastica require annual audiograms. 
  2. All audiometric testing will be conducted for employees exposed to 85 dB or greater over an 8 hour work shift by the Miller Hill Essentia Occupational Health Clinic. Testing must be conducted by an audiologist, physician, or other licensed healthcare professional (PLHC)
  3. Testing will be conducted during the employee’s normal working hours at no cost to the employee.
Baseline Testing
  • This baseline testing must be completed within 6 months of the employees’ first exposure to noise levels over 85 dB. 
  • Employees should be exposed to no workplace noise for at least 14 hours prior to testing. Employees should be scheduled for testing at the start of their shift if possible. If that is not possible, employees should be instructed to wear hearing protection until their appointment. 
  • The baseline test will serve as a comparison for annual testing results. 
Annual Testing
  • Recurring annual testing will be conducted for employees who continue to be exposed to noise levels over 85 dB. 
  • Annual testing will be completed no more than 12 months after the prior year’s test. 
  • The annual audiogram is compared to the baseline audiogram to  determine
    • If the new audiogram is valid
    • If a Standard Threshold Shift (STS) of 10 dB is indicated
  • If a STS is indicated the following steps will be taken:
    • The employee must be notified in writing of the results indicating a STS within 21 days of receiving the results. 
    • The employee will be sent for a retest within 30 days of their annual test which showed a STS.
    • An audiologist, otolaryngologist, or physician will evaluate the initial audiogram that showed a STS. 
  • If the follow-up test confirms a STS:
    • Employees who are not currently using hearing protection will be fitted with hearing protection and trained on their use and care.
    • Employees already using hearing protection will be refitted and retrained. If necessary hearing protection with higher noise reduction ratings will be provided. 
    • Employees will be allowed to select from different types and brands of hearing protection in order to achieve the best fit and comfort level.
    • Employees will be required to wear the hearing protection issued to them if they are working in any area where the noise level is greater than 85 dB. 
    • If additional testing is required, or the hearing protection is suspected of causing an ear problem, the employee will be referred for a clinical audiological evaluation or an otological examination. 
    • For ear problems not related to the wearing of hearing protection, the employee will be informed of the need for an otological examination. 
  • A revised baseline may be established by adopting the most recent baseline if; in the judgement of an audiologist, or physician; a STS is persistent, or the annual audiogram indicates a significant improvement over the original baseline audiogram. 
  • If subsequent annual audiometric testing indicates that the STS is not present for an employee with an 8-hour TWA exposure of less than 90 dBA, the employee will be informed of the new audiometric interpretation. The required use of hearing protection for the affected employee in environments with less than 90 dB of noise may be discontinued. 

Hearing Protection and Noise Level Reduction Controls

  • When possible, loud equipment should be replaced by quieter alternatives. If replacement is not possible, noise dampening controls should be implemented. 
  • Employee work areas or tasks should be rotated to reduce exposure to loud environments. 
  • Hearing protection will be provided at no cost for all employees who may be exposed to an 8 hour TWA noise level of 85 Db or greater, or short term (2 hours or less) noise levels over 90 dB.
  • Hearing protection use is required for employees when any of the following conditions exist
    • Noise level is expected to exceed 85 dB 8-hour TWA
    • Employee does not have a baseline audiogram within 6 months of an initial exposure at or above 85dB 8-hour TWA
    • When a STS has occurred or is suspected
  • A variety of hearing protection devices will be provided in order to achieve the best fit and highest comfort level reasonably achievable.
  • Employees who are required to use hearing protection or choose to use hearing protection will be instructed on how to use them and how to evaluate the protection their selected device offers. 
  • Hearing protection devices must reduce noise levels to 
    • Less than 90 dB 8 hour average if employees do not have a STS
    • Less than 85 dB 8 hour average if an employee has a STS
  • Hearing protection levels will be re-evaluated whenever noise exposure levels change to ensure the noise reduction is sufficient. 
Using the Noise Reduction Rating (NRR)
  • The performance of earplugs and earmuffs varies between brands and styles. One way to choose a hearing protector is to compare Noise Reduction Ratings. The Noise Reduction Rating, or NRR, measures the muff’s or plug’s ability to block out noise or “attenuate” sound. This measurement is stated in decibels; a plug with an NRR of 26 blocks out a maximum of 26 decibels of noise. The NRR listed is the maximum protection that is achievable if the plug fits the wearer perfectly and is inserted correctly. In most work situations, attenuation is half of the listed NRR. For example, if the NRR is 30 the hearing protector most likely blocks out 15 decibels of noise.
  • The following formula is used to assess the NRR of our Hearing Protection Devices:
    • Subtract 7 dB from the NRR if noise is measured on the A- weighted decibel scale (dBA). (Skip this step if noise is measured on the C-weighted dB scale)
    • Divide the result of step 1 (NRR- 7) by 2. This is known as “derating”.
  • An Example of Reducing the NRR
    • 8-hour TWA noise exposure:        93dBA 
    • NRR of hearing protectors:        28dB
    • Subtract 7 from the NRR:        29dB-7dB=22dB
    • Divideby2:        22÷2=11dB
    • Subtract 11 dB from them 8-hour TWA noise exposure:    93dBA-11dB=82dB
    • Decide if 82 dB (the “Protected Exposure”) is below the PEL for noise

Training Requirements

All employees covered by the hearing protection plan must be given training on the procedures, and given the opportunity to ask questions prior to beginning work. 

Staff exposed to noise levels over 85 dB 8-hour TWA will be trained prior to exposure to noise levels greater than 85dB 8-hour TWA and annually on the purpose and importance of hearing protection.

Training must include:    

  • The effects of noise on hearing
  • The purpose of hearing protectors
  • The advantages, disadvantages, and attenuation of the various types of hearing protection devices
  • Instructions on the selection, fitting, use, and care of hearing protection devices
  • The purpose of audiometric testing and an explanation of the test procedures. 

Record Retention

  • All written and electronic records produced by the procedures in this document will be maintained in accordance with the document retention procedures of The College of St. Scholastica. 
  • Training records will be maintained for at least 3 years.
  • Noise level exposure testing records will be maintained for the duration of employment plus 30 years. 
  • Hearing Audiometric testing records will be maintained for the duration of employment plus 30 years. 
    • Audiometric testing records must include:
      • Employee’s name and job title
      • Date of audiogram
      • Examiner’s name and company 
      • Date of last calibration of the audiometer
      • Employee’s most recent noise exposure assessment
      • Audiometric test room background sound pressure level data

Deviation from Procedure

  • Any deviation from this procedure must have prior written approval from the Occupational Safety, Health & Emergency Management Director. Procedure deviations will only be approved on rare occurrences with thorough pre-planning and justification. 
  • Deviations due to process improvements require an update to this written procedure prior to implementation. 

Definitions

  • Audiometric Test: A hearing test which consists of air conduction, pure tones at the minimum frequencies of 500, 1000, 2000, 3000, and 4000 Hz. Both ears will be tested separately. 
  • Audiogram: A chart, graph, or table of audiometric test results showing an individual’s hearing threshold levels at selected frequencies. 
  • Audiologist: A professional specializing in the study or rehabilitation of hearing, who is certified by the American Speech-Language-Hearing Association or licensed by a State Board of Examiners.
  • Baseline Audiogram: The initial audiogram of an employee, against which future audiograms are compared. 
  • Sound: A form of mechanical energy that travels as longitudinal waves through a medium, such as air, water, or solids. Sound is produced when objects vibrate. These vibrations create pressure waves in the surrounding medium, which propagate outward in all directions. When these pressure waves reach our ears, they cause the eardrum to vibrate, which in turn sends signals to the brain that are interpreted as sound.
  • Frequency: The number of vibrations per second, which determines the pitch of the sound. Higher frequency sounds are perceived as higher pitches, while lower frequency sounds are perceived as lower pitches.
  • Hertz (Hz): Unit of measuring the frequency of sound, it refers to the number of cycles per second. 
  • Amplitude: The intensity or loudness of the sound. Higher amplitude sounds are perceived as louder, while lower amplitude sounds are perceived as softer.
  • Wavelength: The distance between successive wave crests or troughs. Wavelength is inversely related to frequency, meaning that higher frequency sounds have shorter wavelengths and lower frequency sounds have longer wavelengths.
  • Decibel (dB): A logarithmic unit of measurement for the intensity or pressure of sound (for every 10 decibel increase, the intensity doubles).
  • Decibel A-Weighted (dBA): Sound level meter readings that have been modified by meter processing to represent the human ear’s response to sound levels at various frequencies. For example, the human ear is less responsive to low frequencies in the 40-100 Hz Range
  • Noise: Unwanted or unpleasant sound that can be harmful to hearing.
  • Noise Level: The intensity of unwanted sound expressed in dB. 
  • Noise Dosimeter: An instrument for measuring noise exposure levels over a period of time. 
  • Noise Reduction Rating (NRR): A measure of the effectiveness of hearing protection devices.
  • Noise Induced Hearing Loss (NIHL): Hearing loss caused by exposure to loud noises. 
  • Standard Threshold Shift (STS): A change in hearing threshold relative to the baseline audiogram of an average of 10 dB or more at 2000, 3000, or 4000 Hz in either ear. 
  • Time-Weighted Average (TWA): An average exposure level over an 8-hour workday.

References

  • “(Re)Evaluate and Document.” Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health (NIOSH), n.d. Web. 19 May 2025.
  • “29 CFR 1910.95 - Occupational Noise Exposure.” Occupational Safety and Health Administration. n.d. Web. 19 May 2025.
  • “29 CFR 1926.52 - Occupational Noise Exposure.” Occupational Safety and Health Administration. n.d. Web. 19 May 2025.
  • “Eliminate or Reduce Noise.” Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health (NIOSH), n.d. Web. 19 May 2025.
  • “Implement Engineering Controls.” Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health (NIOSH), n.d. Web. 19 May 2025.
  • “Provide Hearing Protection.” Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health (NIOSH), n.d. Web. 19 May 2025.
  • “Understand Noise Exposure.” Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health (NIOSH), n.d. Web. 19 May 2025.
  • “Use Administrative Controls.” Centers for Disease Control and Prevention. National Institute for Occupational Safety and Health (NIOSH), n.d. Web. 19 May 2025.
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