C-9 **HEARING CONSERVATION AND NOISE CONTROL**

I. **PURPOSE**

This program ensures hearing conservation and noise control efforts in
areas where employee exposure to noise equals or exceeds levels set
forth in the *Occupational Noise Exposure Standard* (29 CFR 1910.95). To
reduce occupational hearing loss, employees enrolled in the
NCI-Frederick Hearing Conservation Program (HCP) are provided hearing
protection, annual training, and hearing tests.

II\. **DEFINITIONS**

> **Action Level** - A sound level equaling an 8-hour TWA of 85 dBA, or
> equivalently a noise dose of fifty percent, as specified in 29 CFR
> 1910.95.
>
> **Audiogram** -- A chart, graph or table that results from an
> audiometric test. An audiogram show's an individual's hearing
> threshold level as a function of frequency (Hz).
>
> **Baseline Audiogram** - The baseline audiogram is the reference
> audiogram against which future audiograms are compared.
>
> **dBA: Decibels on an A-weighted level** - A measurement of noise
> intensity obtained using a sound measuring instrument; commonly used
> to define degrees of auditory risk. The A-weighting is an measurement
> that closely parallels the auditory characteristics of normal human
> hearing.
>
> **Dosimetry** -- A technique of sound measurement that integrates
> cumulative noise exposure over time and directly indicates a noise
> dose.
>
> **Hearing Conservation Program (HCP)** - An annual audiometric testing
> and hearing conservation training program for employees exposed to
> sound levels equaling or exceeding the action level.
>
> **Hearing Protection Device (HPD)** - Personal protective equipment
> worn by an individual for the purpose of reducing noise exposure
> including reusable and disposable earplugs, ear muffs, and similar
> noise attenuating devices.
>
> **Standard Threshold Shift (STS)** - A change in hearing threshold,
> relative to the baseline audiogram, of an average of 10 decibels or
> more at 2000, 3000, and 4000 Hz in either ear, taking into account any
> changes due to presbycusis (age-related hearing loss).
>
> **Time Weighted Average (TWA)** - Noise exposure averaged over a
> designated period of time. (Example: 8-hour TWA)

III\. **RESPONSIBILITIES**

A.  Occupational Safety Branch (OSB)

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1.  Administers the NCI-Frederick Hearing Conservation program.

2.  Conducts and documents noise surveys areas/activities where
    potential noise exposures may equal or exceed an 8-hour time
    weighted average (TWA) of 85 dBA.

3.  When notified by employee or employee supervisor, performs a sound
    level survey in areas where a change in activity, process, equipment
    or controls may have resulted in either an increase or a decrease in
    employee exposure.

4.  Identifies noise hazard areas and posts appropriate signs.

5.  Provides employees access to noise survey and dosimetry records.

6.  Notifies Occupational Health Services, Supervisor and affected
    employees when monitoring indicates an exposure at or above OSHA's
    Action Level, and participation in the HCP becomes mandatory.

7.  Recommends appropriate engineering and/or administrative noise
    controls.

8.  Develops a training program and ensures annual training of employees
    enrolled in the HCP in hearing conservation issues and practices.

9.  Maintains sound level meters, noise dosimeters, and field
    calibration equipment in accordance with manufacturer's instructions
    and performs or provides for required calibrations in accordance
    with the requirements of 29 CFR 1910.95.

10. Maintains records of all noise monitoring and instrument
    calibration.

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B.  Occupational Health Services (OHS)

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1.  Conducts baseline audiograms and annual audiometric testing on
    employees enrolled in the HCP in accordance with the specifications
    of 29 CFR 1910.95.

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1.  Notifies EHS of employee complaints of potential noise hazard
    exposures.

2.  Ensures the proper selection and fit of HPD's.

3.  Ensures appropriate certification of those responsible for
    audiometric testing, interpretation of audiometric results,
    selection and fit of HPD's, and employee hearing conservation
    training.

4.  Identifies Standard Threshold Shift (STS), subsequent re-testing,
    employee notification, management of those employees with STS, and
    possible referrals.

5.  Assists OSB as needed with the annual training of employees in the
    HCP.

6.  Maintains audiometric testing equipment in accordance with
    manufacturer's instructions and performs or provides for required
    machine calibrations in accordance with the requirements of 29 CFR
    1910.95, Appendix E.

7.  Maintains records of audiometric test results (audiograms), employee
    training, and of noise monitoring results for duration of employment
    plus 30 years.

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C.  Supervisor

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1.  Notifies Occupational Safety Branch of potential noise hazard areas.

2.  Evaluates the feasibility of engineering and/or administrative noise
    controls as recommended by OSB.

3.  Identifies employees exposed to sound levels equaling or exceeding
    the action level to OSB.

4.  Ensures the ready availability of appropriate Hearing Protection
    Devices (HPD's) to employees working in identified noise hazard
    areas.

5.  Enforces the proper use of hearing protection by employees in areas
    where the 8-hour TWA (or its equivalent) equals or exceeds 85 dBA.

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D.  Employee

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1.  Wears HPD's when entering or working in identified noise hazard
    areas in accordance with the posted warning.

2.  Reports potential noise hazard exposures to Supervisor, OSB, or OHS.

3.  Complies with Hearing Conservation Program requirements when
    identified as being exposed to sound levels equaling or exceeding
    the action level.

IV\. **PROGRAM ELEMENTS**

A.  Noise Monitoring

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1.  Noise level surveys of potential noise hazard areas shall be
    conducted periodically.

2.  When area surveys are inappropriate for determining an employee's
    actual noise exposure due to circumstances such as high mobility,
    significant variations in sound level, or a significant component of
    impulse noise, personal noise dosimetry shall be conducted to comply
    with monitoring requirements.

3.  Employees identified as being exposed at or above an 8-hour time
    weighted average of 85 decibels shall be notified with the results
    of the monitoring, and shall be required to enroll in the
    NCI-Frederick Hearing Conservation Program.

4.  Caution signs that clearly indicate a hazard of high noise levels
    and the recommendations/requirements to wear HPD's shall be posted
    at entrance(s) to, and the periphery of, noise hazard areas. In
    areas where work is sporadic (i.e. attics and basements), warning
    signs shall be posted with a reference duration so as not to exceed
    an 8-hour time weighted average of 85 decibels.

5.  Noise dosimetry and area monitoring will be repeated periodically,
    or whenever any changes to facilities, equipment, work practices,
    procedures, or noise-control measures alter potential noise
    exposures.

6.  Instruments used to determine sound levels will be calibrated as
    specified in 29 CFR 1910.95 (Appendix G) and will meet or exceed the
    performance requirements specified in 29 CFR 1910.95 and ANSI S1.4,
    *Specification for Personal Noise Dosimeters* (latest revision).

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B.  Engineering Controls - EHS recommends the use of engineering
    controls as the primary mechanism to attenuate noise emission.
    Engineering controls must meet the technical and economic
    feasibility criteria of the Occupational Safety and Health
    Administration (OSHA).

C.  Administrative Controls - When engineering controls are not
    feasible, or fail to reduce sound levels, EHS recommends
    administrative controls to limit the amount of time that an employee
    works in areas where the 8-hour TWA equals or exceeds 90 dBA. A
    written plan of employee rotation or scheduling of equipment
    operation shall be utilized.

D.  Personal Protective Equipment -- HPD's are provided and must be used
    when feasible engineering and administrative controls fail to reduce
    sound levels to those specified by 29 CFR 1910.95.

The following guidelines for personal protection apply:

1.  HPD's will be available and recommended to be worn by all employees
    when working in areas where sound levels equal or exceed the action
    level.

2.  Employees will be required to wear HPD's when working in areas where
    their anticipated 8-hour TWA sound level would equal or exceed 90
    dBA.

3.  Employees with an STS will wear HPD's during the entire work shift
    when working in areas where the 8-hour TWA sound level equals or
    exceed 90 dBA.

4.  The employee's supervisor will enforce the proper use of HPD's.

5.  Several types of HPD's will be made available to employees, thus
    allowing for personal preference, proper attenuation, and proper
    fit.

6.  All persons entering posted noise hazard areas are to wear HPD's in
    accordance with the posted warning.

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E.  Audiometric Testing - The important elements of an audiometric
    testing program include baseline audiograms, annual audiograms,
    training, and follow-up procedures.

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1.  All audiometric testing shall meet the requirements stated in 29CFR
    1910.95(h). This includes calibration of the audiometer in
    accordance with the requirements of 29 CFR 1910.95 (Appendix E) and
    American National Standard (ANSI) S3.6, *Specification for
    Audiometers* (latest revision). The audiometer shall also meet the
    specifications of, and be maintained and used in accordance with 29
    CFR 1910.95 and ANSI S3.6 (latest revision). The audiometric booth
    and/or room used for testing shall meet the requirements specified
    by 29 CFR 1910.95, Appendix D.

2.  Occupational Health Services (OHS) will provide baseline audiometric
    testing for all new employees within 6 months of an employee\'s
    first exposure at or above an 8-hour TWA of 85 dB.

3.  Audiometric testing for those employees enrolled in the HCP shall be
    conducted at least annually. Annual audiograms shall be compared to
    baseline audiograms to determine if there is a Standard Threshold
    Shift.

4.  If a Standard Threshold Shift (STS) is identified:

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a.  A retest shall be conducted within 30 days to determine if the shift
    is temporary or permanent.

b.  OHS shall notify the employee in writing of the audiometric testing
    results within 21 days of determination.

c.  Employees shall be fitted or refitted with adequate hearing
    protectors, shown how to use them, and required to wear them.

d.  The employee shall be referred for further testing when test results
    are questionable or when problems of a medical nature are suspected.

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5.  Training - Employees exposed to TWAs of 85 dB and above shall be
    trained at least annually in the effects of noise; the purpose,
    advantages, and disadvantages of various types of hearing
    protectors; the selection, fit, and care of protectors; and the
    purpose and procedures of audiometric testing.

6.  Follow-up audiometric testing shall be conducted as necessary to
    ensure that the NCI-Frederick Hearing Conservation Program is
    preventing hearing loss.

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F.  Recordkeeping - EHS shall retain noise measurement records for at
    least 2 years. OHS shall maintain records of audiometric test
    results, training, and the employee's most recent noise exposure
    assessment for the duration of the affected employee's employment,
    plus 30 years.

G.  Program Evaluation -- EHS and OHS will annually review and revise,
    if necessary, the NCI-Frederick Hearing Conservation Program.
    Evaluation will include, but is not limited to: noise level surveys
    results, individual noise exposure risk assessments, audiometric
    monitoring records, training logs, equipment calibration records,
    records of disposition and follow-up actions, clinical records, and
    documents reflecting work-site inspections of employees enrolled in
    the HCP. Any necessary changes shall be made to the HCP at this
    time.

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V.  **REFERENCES**

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A.  American National Standards Institute, New York. Standards:

> \- Specification for Personal Noise Dosimeters, ANSI S1.4
>
> \- Specification for Audiometers, ANSI S3.6

B. Occupational Safety and Health Administration, Washington DC.

> \- Occupational Noise Exposure Standard, 29 CFR 1910.95

\- OSHA 3074: Hearing Conservation