> **KSC**
>
> **HEARING LOSS PREVENTION PROGRAM**

National Aeronautics and

Space Administration

**John F. Kennedy Space Center**

**KSC FORM 16-12 (REV. 6/98)**

**Responsible Office**: Spaceport Services

PREFACE

This Handbook provides guidance to all National Aeronautics and Space
Administration (NASA) personnel wherever KSC has a defined management
responsibility, including the Kennedy Space Center, Cape Canaveral Air
Force Station (CCAFS), the 45th Space Wing, the 30th Space Wing, and
secondary and contingency landing sites, and to their associated
contractors and tenants in accordance with the provisions of their
respective contracts. It provides general and specific guidelines for
protective measures to be taken to prevent occupational hearing loss
among employees exposed to noise.

This Handbook is a complete revision of KHB 1820.3 C.

J. Chris Fairey

Director of Spaceport Services

[Distribution]{.underline}:

#### Tech Doc Library

i/ii

TABLE OF CONTENTS

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| 1.1 |                                                 |              |
| 1 E |                                                 |              |
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| nee |                                                 |              |
| rin |                                                 |              |
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+-----+-------------------------------------------------+--------------+
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|     |                                                 | #### 1-1     |
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|     |                                                 | ##### 1-4    |
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|     |                                                 |              |
+-----+-------------------------------------------------+--------------+
| >   |                                                 | 2‑1          |
| 2\. |                                                 |              |
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| 13  |                                                 |              |
| Emp |                                                 |              |
| loy |                                                 |              |
| ee  |                                                 |              |
| Acc |                                                 |              |
| ess |                                                 |              |
|     |                                                 |              |
| ### |                                                 |              |
| # 2 |                                                 |              |
| .14 |                                                 |              |
|  Re |                                                 |              |
| cor |                                                 |              |
| ds  |                                                 |              |
+-----+-------------------------------------------------+--------------+
|     |                                                 |              |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-1     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | 2-1          |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-1     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-1     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | 2-1          |
+-----+-------------------------------------------------+--------------+
|     |                                                 | 2-2          |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-3     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-4     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-4     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-6     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | 2-7          |
+-----+-------------------------------------------------+--------------+
|     |                                                 | 2-8          |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-8     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | #### 2-8     |
+-----+-------------------------------------------------+--------------+
|     |                                                 | ####         |
+-----+-------------------------------------------------+--------------+
| [   |                                                 |              |
| App |                                                 |              |
| end |                                                 |              |
| ix] |                                                 |              |
| {.u |                                                 |              |
| nde |                                                 |              |
| rli |                                                 |              |
| ne} |                                                 |              |
+-----+-------------------------------------------------+--------------+
| A.  | Table 1, Noise Exposure Limits for Continuous   | A‑1          |
|     | Noise                                           |              |
+-----+-------------------------------------------------+--------------+
|     | Table 2, Noise Exposure Limits for Impact or    | A‑2          |
|     | Impulsive Noise                                 |              |
+-----+-------------------------------------------------+--------------+
|     | Table 3, Maximum Background Sound Pressure      | A‑3          |
|     | Levels for Audiometric Test Rooms               |              |
+-----+-------------------------------------------------+--------------+
|     |                                                 |              |
+-----+-------------------------------------------------+--------------+
| B.  | Definitions                                     | B‑1          |
+-----+-------------------------------------------------+--------------+

iii

[List Of References]{.underline}

OSHA Standard 29 CFR 1910.95, \"*Occupational Noise Exposure*\"

OSHA Standard 29 CFR 1926.52, \"*Occupational Noise Exposure"*

29 CFR 1904, "*Recording and Reporting Occupational Injuries and
Illnesses"*

American National Standards Institute, \"*Specification for Sound-level
Meters*,\" ANSI Sl.4‑1994

American National Standards Institute, \"*Specification for Personal
Noise Dosimeters*,\" ANSI Sl.25‑1991

American National Standards Institute, "*Maximum Permissible Ambient
Noise Levels for Audiometric Test Rooms",* ANSI S3.1-1999

American National Standards Institute, \"*Specifications For
Audiometers*\", ANSI S3.6‑1996

American National Standards Institute, "*Measurement of Sound Pressure
Levels in Air*," ANSI S1.13-1995

American National Standards Institute, " *Measurement of Occupational
Noise Exposure*", ANSI S12.19 -- 1996.

## Privacy Act of 1974 as amended (5 USC Sec.552a *Records Maintained on Individuals*) 

American Conference of Governmental Industrial Hygienists, "*Threshold
Limit Values for Chemical Substances and Physical Agents and Biological
Exposure Indices".*

National Institute for Occupational Safety and Health (NIOSH),
*Occupational Noise Exposure -- Revised Criteria 1998.*

Air Force Occupational Safety and Health (AFOSH) Standard 48-19
*Hazardous Noise Program.*

iv

### SECTION 1

FUNCTIONAL RESPONSIBILITIES

1.  The KSC Occupational Medicine Officer, or designated representative,
    is responsible for:

    a.  Providing medical evaluations, obtaining occupational history of
        participants in the Hearing Conservation Program, and evaluating
        test results.

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    ```
    a.  Maintaining a record of personnel receiving Hearing Conservation
        Program physical examinations and providing audiometric
        examinations for those persons.

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    a.  Notifying employees in accordance with this KHB of significant
        hearing loss or other medical pathology of the ear, and
        explaining the need and plans for further testing and/or
        referrals.

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    ```
    a.  Notifying the employee and his/her employer within 21 days if
        further testing establishes a standard threshold shift or
        deafness has occurred and initiating an industrial hygiene
        follow-up investigation of the employee's workplace.

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    a.  Recommending the reassignment of employees to work in low noise
        areas, when necessary to prevent further significant hearing
        loss or the aggravation of other medical conditions that could
        be worsened by work in a high noise area.

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    a.  Referring employees to an audiologist or physician specialist,
        as appropriate.

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    a.  Ensuring physicians who conduct or supervise the audiometric
        testing of employees have reviewed the requirements of this
        standard and 29 CFR 1910.95.

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    ```
    a.  Ensuring audiometric tests are performed by a licensed certified
        audiologist, otolaryngologist, or other physician, or by a
        technician under the supervision of a physician or audiologist.
        Technicians who perform audiometric tests using microprocessor
        audiometers shall satisfactorily demonstrate competence in
        administering automatic audiometric examinations, obtaining
        valid audiograms, and properly using the audiometers.
        Technicians who perform manual audiograms shall be certified by
        the Council of Accreditation in Occupational Hearing
        Conservation.

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    <!-- -->
    ```
    a.  Ensuring audiometric test equipment is properly calibrated and
        ambient noise levels in the audiometric test rooms meet the
        requirements within this KHB.

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    ```
    a.  Maintaining audiometric test records and other records.

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    a.  Providing employee access to medical records in accordance with
        the requirements of paragraph 2.14.

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    a.  Providing audiometric examinations and notifying employees of
        the need to avoid exposure to high noise levels preceding the
        audiometric test.

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1.  The Workforce and Diversity Management Office will coordinate
    reassignment of employees with the Occupational Medicine Officer as
    required by paragraph 1.1.e.

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2.  The J-BOSC Technical Training Office, or other contractor training
    organizations will, to the extent provided by contract, provide
    hearing conservation program training and maintain associated
    employee training and certification records in accordance with the
    requirements of 29 CFR 1910.95.

3.  The KSC Industrial Hygiene Officer, or a designated representative,
    is responsible for

    a.  Providing baseline surveys on notification of each new
        operation, job, or procedure having the potential of creating a
        noise hazard.

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    a.  Providing monitoring of hazardous, or potentially hazardous,
        noise areas or operations, including personnel noise dosimetry.

    b.  Providing follow-up investigations of employee workplaces for
        employee's with an identified Standard Threshold Shift.

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    a.  Providing the results of noise surveys and recommendations for
        control of noise hazards to supervisors, site managers, and
        responsible safety organizations in the affected work areas.

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    a.  Notifying the employers of affected employees of the results of
        noise dosimetry monitoring.

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    a.  Reviewing facility and operational plans to assess the adequacy
        of precautions taken to control noise exposures.

    b.  Recommending methods to control hazardous noise exposure.

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    ```
    a.  Maintaining records of noise surveys and providing employee
        access to those records.

4.  The KSC Hearing Conservation Program Officer, or designated
    representative, is responsible for:

    a.  Implementing and administering the Hearing Conservation Program.

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    ```
    a.  Designating hazardous noise areas and notifying the work area
        supervision, the Environmental Health Officer, and the safety
        office of such areas.

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    a.  Maintaining an inventory of high noise areas including noise
        levels recorded in those areas.

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    ```
    d.  Notifying supervisors of the requirements for employees to
        participate in the Hearing Conservation Program when monitoring
        data shows the employee\'s noise exposure exceeds the criterion
        for enrollment.

    e.  Ensuring the implementation and adequacy of training provisions
        for NASA personnel.

    f.  Recommending and evaluating the selection of hearing protection
        devices to assure they provide adequate attenuation.

    g.  Coordinating with the Occupational Medicine Officer, or
        designated representative to determine workplace causes of
        standard threshold shifts.

    h.  Monitoring background noise levels in audiometric booths used at
        the Kennedy Space Center.

5.  Contractor Safety and Health program personnel are responsible for:

    a.  Referring personnel who complain of hearing loss or other
        hearing or ear problems to the Occupational Health Facility.

    b.  Enforcing the wearing of hearing protection devices, the posting
        of warning signs and labels, and implementation of
        administrative controls.

    c.  Notifying the Hearing Conservation Program Officer, or his/her
        designated representatives, of any known changes in operations
        or procedures which increase/decrease personnel exposure to
        noise.

    d.  Reporting notifications of work-related hearing loss to the NASA
        mishap reporting system.

6.  Heads of Primary organizations and Heads of Contractor Organizations
    are responsible for:

    a.  Implementing engineering and work practice controls where
        required to reduce or eliminate noise hazards.

    b.  Ensuring employees are provided Hearing Conservation Program
        training in accordance with 29 CFR 1910.95 and this Handbook

7.  Supervisors are responsible for:

    a.  Reporting suspected noise hazards in all their areas of
        jurisdiction to the Hearing Conservation Program Officer, or to
        designated representative.

    b.  Providing the Occupational Health Facility with the names of
        personnel working in hazardous noise areas or noise exposed jobs
        when identified by the Hearing Conservation Officer.

    c.  Referring personnel who complain of hearing loss or other
        hearing or ear problems to the Occupational Health Facility.

    d.  Ensuring that employees keep their appointments at medical
        facilities for Hearing Conservation Program examination.

    e.  Ensuring the provision of hearing protection devices, as
        identified by the KSC Industrial Hygiene Officer, enforcing the
        wearing of hearing protection devices, and implementing
        recommended administrative controls

    f.  Notifying the Hearing Conservation Officer, or his designated
        representatives, of any changes in operations or procedures
        which increase/decrease personnel exposure to noise.

    g.  Ensuring employees who are participants in the Hearing
        Conservation Program attend annual training.

    h.  Attending Hearing Conservation Program training.

    i.  Notifying his/her affected employees of the results of noise
        surveys.

    j.  Notifying each affected employee of the results of noise
        dosimetry monitoring

    k.  Ensuring warning signs are posted at locations specified by the
        Hearing Conservation Officer.

    l.  Scheduling an exit audiometric examination prior to the
        employee\'s termination, transfer to another position, or
        retirement when possible and if an audiogram has not been
        performed within six months of departure.

8.  Individual Employees are responsible for:

    a.  Following control procedures established for maintaining
        effective noise exposure control, including wearing and
        maintaining hearing protective devices furnished for their
        protection.

    b.  Cooperating with supervisors, medical, environmental, and safety
        personnel in actions to evaluate noise hazards and to prevent
        hearing loss caused by excessive exposure to workplace noise.

    c.  Notifying supervisors of areas, operations, or equipment that
        may be a noise hazard.

    d.  Attending training courses and keeping medical appointments as
        required by this Handbook.

9.  Facility Managers are responsible for posting warning signs on
    facility equipment and entrances to high noise areas, in accordance
    with paragraph 2.5.

10. Heads of engineering organizations are responsible for:

    a.  Assuring new facilities and equipment are designed, procured,
        operated, and maintained in such a manner, where feasible, as
        not to create a noise hazard.

    b.  Designing and implementing engineering methods to reduce noise
        from existing facilities or equipment that constitute a noise
        hazard.

    c.  Coordinating the design and implementation of engineering noise
        control measures with the KSC Industrial Hygiene Officer.

    d.  Notifying the KSC Hearing Conservation Officer, or designated
        representative, of any changes in operations or procedures which
        increase/decrease personnel exposure to noise.

SECTION 2

HEARING LOSS PREVENTION PROGRAM

1.  General

    The Hearing Loss Prevention Program includes elements toward a goal
    of preventing hearing loss and includes the observance of noise
    exposure limit, exposure assessments, engineering controls,
    administrative controls, hearing protection devices, medical
    surveillance, hazard communication, training and records management

2.  Noise Exposure Limits

    a.  The noise exposure limit for an employee is an eight hour
        time-weighted average of 85 decibels, A-weighted (85 dBA 8-hr
        TWA) or an equivalent dose based on Table 1 (Appendix A).
        Exposures at or above 100% of the noise dose are considered
        hazardous. Unprotected exposures above 115 dBA are not allowed
        for any duration.

    b.  Exposure to impact or impulse noise shall not exceed the limits
        listed in Table 2. No exposures in excess of 130 dB peak sound
        pressure level are permitted regardless of hearing protection.

    c.  An employer must enroll personnel in the Hearing Conservation
        Program if employee routine (30 days or more per year) noise
        exposure equals or exceeds the Action Level (80 dBA 8-hr TWA or
        equivalent dose).

3.  Engineering Control of Noise

    a.  Where feasible, facilities and equipment will be procured,
        designed, operated, and/or modified to prevent employee exposure
        to continuous noise levels at or above 85 dBA or impulsive noise
        above 130 dB. Any reduction in noise level even if it is not
        reduced below 85 dBA is essential.

    b.  If controls fail to reduce sound levels within the limits of
        Tables 1 and 2, a warning sign must be posted and hearing
        protection devices and/or administrative methods of noise
        exposure protection must be used.

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1.  Administrative Control

    Access of personnel to noise hazard shall be restricted to the
    minimum number and/or period of time required to perform a specific
    task or function. Where Hearing Protection Devices are not
    sufficient to attenuate noise to less than 85 dBA 8-hr TWA, the
    duration of time spent in the noise hazard area will be limited, not
    to equal or exceed the exposure limits in Table 1 and Table 2.

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1.  Warning Signs

    a.  When noise levels routinely equal or exceed 85 dBA 8-hr TWA,
        warning signs which clearly indicate the hazard of high noise
        levels and state the requirement to wear hearing protection will
        be posted at the entrances to the area.

    b.  Decals or placards warning of the potential noise hazard will be
        affixed to shop tools and machines that produce noise equal to
        or greater than 85 dBA at the operator\'s position.

    c.  Warning signs and decals shall have wording in black letters on
        a yellow or orange background.

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4.  Hearing Protection Devices

    a.  Earmuffs and/or plugs will be provided in accordance with 29 CFR
        1910.95 and this Handbook. Such equipment shall be issued for
        the exclusive use of each employee and shall not be traded or
        shared.

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    b.  Personnel must wear hearing protection whenever engineering and
        administrative controls do not reduce employee noise exposure
        below the Action Level. Additionally, all persons working within
        a posted hazardous noise area without regard to their exposure
        duration must wear hearing protection when noise is present. The
        use of hearing protection is recommended for all employees
        operating equipment with sound levels exceeding 85dBA.

    c.  Hearing protectors must attenuate the employee\'s noise exposure
        to a level below the noise exposure limit of 85 dBA 8-hr TWA. A
        combination of both earmuffs and plugs is required where noise
        levels equal or exceed 100 dBA 8-hr TWA, and any exposure equal
        to or greater than 110 dBA. For those with a Standard Threshold
        Shift (STS), protectors must attenuate exposure to an 8-hr TWA
        of 80 dBA. Estimation of the adequacy of hearing protector
        attenuation should be performed according to a method specified
        in 29 CFR 1910.95, Appendix B. A de-rating of the noise
        reduction rating (NRR) of 25% for muffs, and 50% for plugs
        should be used, or the direct application of the SF value from
        subject fit data based on ANSI S72-1998.

    d.  The adequacy of hearing protector attenuation shall be
        reevaluated whenever the employee\'s noise exposure increase to
        a level where the hearing protector provided may no longer
        provide adequate attenuation. More effective hearing protectors
        shall be provided when necessary.

    e.  Where reusable earplugs are used, they will be permanently
        issued to the employee, the employee must be instructed in the
        proper method of insertion and cleaning of the earplugs.
        Employees will inspect reusable earplugs for cleanliness and to
        ensure that they are not damaged prior to each use. Damaged
        earplugs will not be used.

    f.  The user must inspect earmuffs on a regular basis. Earmuffs that
        have been damaged, altered, or modified in any way shall not be
        used in hazardous noise environments. Where replacement parts,
        such as ear cup seals are available, the earmuffs may be
        repaired and reused.

    g.  Special hearing protection equipment, such as sound-suppression
        communications and active noise reduction headsets may be used
        in hazardous noise environments. These devices will be regularly
        inspected by the issuing agency. Headsets that have been
        damaged, altered, or modified shall not be used in hazardous
        noise environments. Where headsets cannot be permanently issued
        to individuals, the issuer must assure the headsets are cleaned
        and sanitized before re-issuance.

5.  Exposure Monitoring

    a.  An initial investigation of potentially hazardous sound levels
        will be conducted when any information, observation, or
        calculation shows an employee may be exposed to a noise level of
        80 dBA 8-hr TWA or greater. This identification includes, but is
        not limited to, representative measurements of noise exposure,
        employee complaints of excessive noise, or any areas where it is
        difficult to understand a normal conversation when the speaker
        and listener face each other at a distance of 2 feet. Any new
        equipment, operation, job, or procedure with the potential for
        creating hazardous noise should be evaluated prior to start up.

    b.  When any initial determination indicates any employee\'s noise
        exposure may equal or exceed 85 dBA 8-hr TWA, area noise
        monitoring will be conducted to establish the characteristics of
        the noise source, operations in the noisy area, the extent of
        the area which exceeds 85 dBA, the number of affected employees,
        and their exposure duration/frequency.

    c.  When an initial determination shows any employee or group of
        employees may be exposed to noise at or above 85 dBA 8-hr TWA,
        noise dosimetry monitoring will be conducted to determine the
        noise dose of the exposed employee and the representative
        exposure of similarly exposed employees, and to determine
        appropriate noise abatement techniques. Where required, an
        octave band analysis will be conducted to determine the
        characteristics of the noise source and to enable the selection
        of engineering controls.

    d.  Monitoring which is representative of the noise exposure of
        employees in the work area will be performed and repeated
        whenever any changes to facilities, equipment, work practices,
        procedures, or noise control measures could increase personal
        noise exposure.

    e.  Employees and/or their representatives will be provided an
        opportunity to observe noise dosimetry and area monitoring
        activities.

    f.  Affected employees will be notified in writing of the results of
        noise dosimetry monitoring within 30 days of receipt of
        monitoring results.

    g.  As a minimum, sound-level meters will meet the Type II
        requirements of ANSI Sl.4-1994 and shall be capable of measuring
        sound in the range of 80‑130 dBA. Measurement will be in
        accordance with ANSI S1.13-1995.

    h.  Noise dosimeters shall meet the Class 2A‑90/80‑5 requirements of
        ANSI Sl.25-1991 and will be capable of integrating sound levels
        of 80 dB and above. Measurements will be made in accordance with
        ANSI S12.19-1996.

    i.  Noise exposure monitoring may be conducted using either a noise
        dosimeter or a sound-level meter. Where a sound-level meter is
        used to estimate an employee\'s noise dose, the survey will
        include a time and motion study to document the variations in
        the employee\'s noise exposure during the working shift.

6.  Hearing Conservation Program Enrollment

    a.  Whenever an employee is occupationally exposed for 30 or more
        days per year to noise at or above 80 dBA 8-hr TWA (50% dose),
        or to impact or impulsive noise in excess of the limits listed
        in Table 2, the employee will be enrolled in a Hearing
        Conservation Program. For the purposes of Hearing Conservation
        Program enrollment, the employee\'s noise exposure shall be
        determined without regard to any sound attenuation provided by
        the use of hearing protectors.

    b.  Prior to placement in a job requiring participation in the
        Hearing Conservation Program, each employee will undergo an
        examination by a qualified physician. The examination will
        include a baseline audiogram, a medical examination to determine
        any preexisting medical pathology of the ear, and a work history
        to document past noise exposure. If an employee is determined to
        be suffering from an acute disease of the ear, which may
        compromise the validity of the test, the baseline audiogram will
        be delayed until the condition has abated.

    c.  When a physical examination cannot be obtained prior to
        placement in a job requiring participation in the Hearing
        Conservation Program, or when it is discovered those already
        assigned to noise-hazard areas have not had a physical exam, one
        shall be conducted within 30 days thereafter. The baseline
        audiogram must be preceded by a period of at least 14 hours,
        during which there is no known exposure to sound levels in
        excess of 80dBA. This time interval should be sufficient to
        allow recovery from noise-induced temporary threshold shift.

    d.  Employees exhibiting a preexisting medical pathology will
        require a review prior to being assigned to work in conditions
        that may aggravate their medical condition. This includes
        persons who are considered legally deaf, hearing disabled, or
        who exhibit medical pathologies that prohibit the use of hearing
        protectors.

    e.  All employees who are enrolled in the Hearing Conservation
        Program will receive an annual audiogram.

7.  Audiometric Testing

    a.  An audiologist, otolaryngologist or other qualified physician,
        occupational health nurse or technician may perform audiometric
        testing. Technicians and nurses who perform audiometric tests
        must be under the supervision of an audiologist,
        otolaryngologist, or other physician. If manual audiometers are
        used, personnel must be certified by the Council for
        Accreditation in Occupational Hearing Conservation. Hearing
        threshold levels will be determined by audiometers calibrated to
        the zero reference levels of the ANSI S3.6‑1996 standard for
        audiometers.

    b.  Audiometric tests will consist of pure tone, air conduction,
        hearing threshold exams with test frequencies at 500, 1000,
        2000, 3000, 4000, 6000, and 8000 Hz in each ear. Audiometric
        test equipment shall meet the specifications, maintenance and
        use requirements of ANSI S3.6-1996. Where a pulsed-tone,
        self-recording audiometer is used, it will also meet the
        requirements of 29 CFR 1910.95 Appendix C.

    c.  The audiologist or audiometric technician will perform a
        listening check, daily, prior to use, to assure the device is
        free from distorted or unwanted sounds.

    d.  A functional test shall be performed each day, either using an
        \"acoustical ear\" calibrator (dBA) SLM with 9A Type Earphone
        Coupler) or a \"biological check,\" by testing an individual
        with a known and stable hearing baseline. A record will be kept
        of the daily tests. Deviations of 5 dB or more require an
        acoustical calibration test.

    e.  An electroacoustic calibration test (using a SLM, octave band
        filter set and a National Bureau of Standards 9A Coupler) will
        be performed at least annually (semiannually for self‑recording
        audiometers) or when a listening check indicates a deviation of
        5 dB or more. The calibration test will conform to the
        requirements of 29 CFR 1910.95 Appendix E. Deviations of 10 dB
        or more will initiate an exhaustive calibration.

    f.  A complete calibration will be performed at least every 2 years
        or whenever an acoustic calibration test indicates an error of
        10 dB or more. The tests will meet the criteria of ANSI
        S3.6-1996. Following the calibration, the front panel of the
        audiometer will be labeled with a tag indicating calibration to
        ANSI S3.6-1996 and the date of the calibration.

    g.  Rooms used for audiometric testing shall not have background
        sound pressure levels exceeding those in Table 3. Sound pressure
        levels in rooms used for audiometric testing should be tested at
        least annually.

    h.  Annual audiograms must be preceded by at least 14 hours without
        exposure to workplace noise. Hearing protectors may be used to
        prevent noise exposure during this period. Employees will be
        notified, in writing, of the need to avoid high levels of
        occupational and non-occupational noise during the 14 hours
        preceding the audiometric test.

    i.  In addition to audiometric test data, each audiogram will, as a
        minimum, identify, the audiometric reference level to which the
        audiometer was calibrated at the time of testing; the date of
        the audiogram; the examiners name; the date of the last
        calibration of the audiometer; and the name, employee number,
        and job classification of the individual tested.

    j.  A qualified physician will compare the employee\'s baseline
        audiogram to the Annual audiogram to determine if the audiogram
        is valid and if a standard threshold shift (STS) has occurred.
        When determining if a standard threshold shift has occurred,
        allowance may be used for the contribution of aging to the
        hearing threshold level by adjusting the audiogram. The
        procedure described in 29 CFR 1910.95 Appendix F will be used.
        The age correction Table F-1 and F-2 may be extrapolated for
        personnel older than 60 years.

    k.  When the evaluation of an audiogram indicates a standard
        threshold shift has occurred, a retest shall be scheduled within
        30 days to determine if the shift is permanent. A permanent STS
        has occurred when the retest confirms the original audiogram
        results.

    l.  The annual audiogram may be substituted for the baseline
        audiogram when, in the opinion of the audiologist,
        otolaryngologist, or examining physician, the hearing threshold
        shown in the annual audiogram indicates a permanent threshold
        shift or significant improvement over the baseline audiogram.
        This audiogram will be used for comparisons with future annual
        audiograms.

    m.  If a permanent STS is determined, the employee will be evaluated
        by a physician to determine if the hearing loss is most likely
        noise induced or whether other medical pathology is suspected.
        The Record of Injury Form (KSC Form 6-2) will be used to notify
        the employee's supervisor, safety office, Workers' Compensation
        office, KSC Hearing Conservation Officer and JBOSC Environmental
        Health of a permanent STS. A separate letter is provided to the
        employer for use to ensure compliance with OSHA requirements
        that employees be provided written notification of STS and
        audiogram results by the employer. If further evaluation by an
        audiologist or otolaryngologist is requested to provide further
        testing or to diagnose other pathology, the request for referral
        will be indicated on the KSC Form 6-2. If it can be determined
        that the STS is not work related or aggravated by occupational
        noise exposure, a KSC 6-2 will not be completed, although a new
        reference audiogram may need to be established.

8.  Medical Referrals

    a.  Criteria for referral to an audiologist

        1.  Baseline Audiogram indicating:

            Average loss greater than 25 dB for 500, 1000,2000 and 3000
            Hz in either ear.

            Average difference between ears of:

            greater than 15 dB for 500, 1000, and 2000 Hz, or

            greater than 30 dB for 3000, 4000,and 6000 Hz

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        1.  Annual Audiogram indicating:

> Change for the worse in average hearing level in either ear compared
> to the baseline audiogram:

greater than 15 dB for 500, 1000, and 2000 Hz, or

greater than 20 dB for 3000, 4000, and 6000 Hz

3.  Variable or inconsistent responses or unusual hearing loss curves.

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a.  Criteria for examination by a qualified physician

    1.  Presence and persistence of ear pain; drainage; dizziness;
        severe persistent tinnitus; sudden, fluctuating or rapidly
        progressive hearing loss, fullness or discomfort in one or both
        ears; or a history of these within the last 12 months.

    2.  Where an employee has previously received an otologic evaluation
        on the basis of failing on the above criteria, a re-evaluation
        should be done if ear pain, drainage, dizziness, severe
        persistent tinnitus develops, or if a significant change in
        hearing levels is observed.

    3.  Where an employee suspects a medical pathology of the ear is
        caused or aggravated by the use of hearing protectors.

    4.  A person possesses good hearing in only one ear (severe
        unilateral loss),

    5.  A person who has chronic otologic problems (such as chronic
        otitis media or chronic otitis externa, especially if the
        condition prevents use of personal hearing protection,

    6.  A person with diplacusis, fullness, inconsistent audiometric
        findings or other puzzling ear symptoms, and

    7.  Where the examining physician refers an employee to a physician
        specialist, communication of relevant medical data will be
        provided upon request.

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9.  Follow-up Review

> **\*** When a work‑related hearing loss is detected, a follow-up
> review will be conducted.

a.  The employee\'s work area will be investigated to determine if work
    practices or changes in equipment or procedures have increased the
    noise hazard.

b.  Work-related hearing loss will be reported to the KSC/NASA mishap
    reporting system. Hearing loss that meets the definition of deafness
    will be reported as a Class B mishap. Other less serious hearing
    loss as defined in 29 CFR 1904,10 will be reported as an incident.

c.  The employee will be retrained on the hazardous effects of noise and
    the need to use hearing protection.

d.  The employee will be refitted with hearing protectors offering
    greater sound attenuation, if needed.

e.  When hearing protectors have not been previously used, the employee
    will be fitted with hearing protectors and will be provided training
    in their use.

f.  The employee's supervision and responsible safety office will be
    notified of the occurrence of a Standard Threshold Shift or other
    work related hearing loss and any necessary abatement actions
    identified in the follow-up investigation of the employee's
    workplace.

g.  When an OSHA recordable standard threshold shift has occurred,
    employers will record the condition as a hearing loss on the OSHA
    300 Log and maintain the record in accordance with 29 CFR 1904,
    *Recording and Reporting Occupational Injuries and Illnesses*.

h.  The employee will be reassigned to work in a low-noise area when
    recommended by a physician to prevent a compensable hearing loss.
    These employees will continue to participate in the Hearing
    Conservation Program.

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10. Employee Training

    a.  Each employee who participates in the Hearing Conservation
        Program will receive annual training. The training must include,
        as a minimum, an overview of the program, a review of the
        effects of noise on hearing; the purpose of hearing protectors;
        the advantages, disadvantages, and attenuation characteristics
        of various types of protectors; noise control principles;
        instruction on selection, fitting, use, and care of hearing
        protectors; and an explanation of the audiometric testing
        procedure and the purpose of audiometric testing.

    b.  Personnel will be encouraged to use hearing protectors whenever
        they are exposed to noise during off‑duty activities (e.g., from
        lawn mowers, firearms, etc.).

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    c.  Supervisors of personnel participating in the Hearing
        Conservation Program shall also receive hearing conservation
        training.

11. Employee Access

    Copies of this Handbook, 29 CFR 1910.95 (OSHA Occupational Noise
    Exposure), and any appropriate records regulated by this standard
    will be provided, upon request, to employees, former employees,
    representatives of employees, representatives of the U.S. Department
    of Labor, National Institute for Occupational Safety and Health
    (NIOSH), and NASA Headquarters Staff personnel. Privacy Act
    provisions will be adhered to as applicable. The current version of
    this Handbook is available electronically on Business World and
    through the JBOSC Environmental Health web site.

12. Records

> Audiograms, employee noise exposure measurements, measurements of the
> background sound pressure levels of audiometric test rooms, and
> employee training records shall be maintained in accordance with the
> requirements of 29CFR 1910.95.

Appendix A

TABLE 1

####### Noise Exposure Limits ^1^

+---------------------+------------------+-----------------------------+
| ####### [Du         |                  | ####### [Exp                |
| ration]{.smallcaps} |                  | osure Level^2^]{.smallcaps} |
|                     |                  |                             |
|                     |                  | **dBA**                     |
+---------------------+------------------+-----------------------------+
| **(hours)**         | **(minutes)**    |                             |
+---------------------+------------------+-----------------------------+
| **16**              | **960**          | **80**                      |
+---------------------+------------------+-----------------------------+
| **8**               | **480**          | **85**                      |
+---------------------+------------------+-----------------------------+
| **4**               | **240**          | **90**                      |
+---------------------+------------------+-----------------------------+
| **2**               | **120**          | **95**                      |
+---------------------+------------------+-----------------------------+
| **1**               | **60**           | **100**                     |
+---------------------+------------------+-----------------------------+
| **0.5**             | **30**           | **105**                     |
+---------------------+------------------+-----------------------------+
| **0.25**            | **15**           | **110**                     |
+---------------------+------------------+-----------------------------+
| **0.125 or less**   | **7.5 or less**  | **115**                     |
+---------------------+------------------+-----------------------------+

> ^1^ Using:
>
> exchange rate =, 5 dB

lower threshold = 80 dB,

> T=480/2^(L-85)/3^ where T=time in min. and L=exposure level
>
> Meter set to slow response
>
> ^2^ The exposure noted for each sound level for the duration noted is
> equivalent to 100% of the allowed noise dose. The Action Level is any
> exposure equivalent to 50% of the exposure duration in this Table.

TABLE 2

### **Noise Exposure Limits For Impact or Impulsive Noise**

+-------------------------------+--------------------------------------+
| ######## **Sound Level**      | **[Permitted Number                  |
|                               | of]{.smallcaps}**                    |
| **(dB)\***                    |                                      |
|                               | **[Impulses or Impacts per           |
|                               | day]{.smallcaps}**                   |
|                               |                                      |
|                               | **(imp/day)**                        |
+-------------------------------+--------------------------------------+
| \>130                         | none                                 |
+-------------------------------+--------------------------------------+
| 130                           | 100                                  |
+-------------------------------+--------------------------------------+
| 120                           | 1,000                                |
+-------------------------------+--------------------------------------+
| 110                           | 10,000                               |
+-------------------------------+--------------------------------------+
| \**Decibels peak sound        |                                      |
| pressure level measured with  |                                      |
| a Type I/II sound level meter |                                      |
| with peak hold feature using  |                                      |
| C-weighting or linear scale   |                                      |
| at fast response.*            |                                      |
+-------------------------------+--------------------------------------+

TABLE 3

####### Maximum Background Sound Pressure Levels

**for Audiometric Test Rooms**

+-------------------------------+--------------------------------------+
| ####### [Oc                   | ######                               |
| tave Band Center]{.smallcaps} | # [Sound Pressure Level]{.smallcaps} |
|                               |                                      |
| #                             | **(dB)**                             |
| ###### [Freqency]{.smallcaps} |                                      |
|                               |                                      |
| **[(]{.smallcaps}Hertz)**     |                                      |
+-------------------------------+--------------------------------------+
| 500                           | 27                                   |
+-------------------------------+--------------------------------------+
| 1000                          | 26                                   |
+-------------------------------+--------------------------------------+
| 2000                          | 34                                   |
+-------------------------------+--------------------------------------+
| 4000                          | 37                                   |
+-------------------------------+--------------------------------------+
| 8000                          | 37                                   |
+-------------------------------+--------------------------------------+
| 1000 to 8000 Hz based on ANSI |                                      |
| S3.1; exceeds 29 CFR 1910.95  |                                      |
| & AFR 161-15; 500 Hz based on |                                      |
| AFR 161-15 and exceeds 29 CFR |                                      |
| 1910.95                       |                                      |
+-------------------------------+--------------------------------------+

DEFINITIONS

1.  [Action level]{.underline}: Continuous noise greater than or equal
    to a noise dose in excess of 50 percent of the noise exposure limits
    listed in Appendix A, Table 1, measured with a dosimeter or
    sound-level meter on the A‑weighted scale, slow response. The action
    level is criterion for workplace monitoring. When average exposures
    exceed this and yet none exceed the exposure limit, this is a
    criterion for participation in the Hearing Conservation Program.

2.  [Administrative controls]{.underline}: Any procedure limiting daily
    exposure to noise by control of the work schedule or operation.

3.  [Annual Audiogram]{.underline}: Annual audiometric test, obtained
    subsequent to the baseline audiogram, which is used to detect shifts
    in the individual\'s threshold of hearing.

4.  [Audiogram]{.underline}: Chart, graph, or table resulting from an
    audiometric test. An audiogram shows an individual\'s hearing
    threshold levels as a function of frequency.

5.  [Audiologist]{.underline}: Professional specializing in the study
    and rehabilitation of hearing, which is certified by the American,
    Speech, Hearing, and Language Association, or licensed by a state
    board of examiners.

6.  [Audiometer]{.underline}: Electronic instrument used for measuring
    hearing threshold levels that conforms to requirements and
    specifications of ANSI S3.6-1996.

7.  [Baseline Audiogram]{.underline}: Audiogram against which future
    audiograms are compared.

8.  [decibel (dB)]{.underline}: A unit of measurement of sound pressure
    level.

9.  [dBA (decibels A‑weighted)]{.underline}: Unit of measurement of
    sound level corrected to the A‑weighted scale (reference ANSI
    Sl.4-1994), as measured by a sound level meter.

10. [Deafness]{.underline}: The otological condition in which the
    hearing threshold level for speech, or the average hearing threshold
    level for pure tones at 500, 1000, 2000, and 3000 Hz is at least 93
    dB (reference ANSI S3.6-1996). This is generally accepted as
    representing a hearing loss disability for normal speech.

11. [Diplacusis]{.underline}: Condition in which one sound is heard
    differently by the two ears, resulting in the perception of two
    sounds instead of one.

12. [Engineering control]{.underline}: Any mechanical device or physical
    barrier that reduces the sound level at the source of noise or along
    the path of propagation of the noise to the individual, not
    including personal protective equipment such as ear muffs or plugs.

13. [Exchange rate]{.underline}: The increase in sound level allowed for
    a corresponding halving of exposure time. (Also called doubling rate
    and trading ratio.)

14. [Hertz (Hz)]{.underline}: A unit or measurement of frequency,
    numerically equal to cycles per second.

15. [Impulsive or Impact noise]{.underline}: Variations of noise level
    involving peaks of intensity occurring at intervals of more than one
    second. If the noise peaks occur at intervals of less than one
    second, the noise is considered continuous.

16. [Medical pathology]{.underline}: Disorder or disease. For the
    purposes of this Standard, a condition or disease affecting the ear,
    which a physician specialist should treat.

17. [Noise]{.underline}: Generally unwanted sound. May also include
    desired sound (PA systems, alarms, etc.).

18. [Noise Dose]{.underline}: A cumulative measure of noise exposure
    which takes into account both the intensity of sounds and the
    duration of exposure to noise during the work shift.

19. [Noise Dosimeter]{.underline}: An electronic instrument that
    integrates cumulative noise exposure over time and measures noise
    dose.

20. [Hazardous Noise]{.underline}: A noise hazard exists wherever any
    operation, process, or procedure generates noise of sufficient
    duration and intensity to be capable of producing a permanent loss
    of hearing to unprotected persons when exposed over a working
    lifetime.

21. [Hazardous Noise Area]{.underline}: Any work area where personnel
    could be exposed to noise levels equivalent to 85 dBA 8-hr TWA or
    greater; continuous or intermittent noise above 115 dB; or a peak
    sound pressure of 130 dB.

22. [Noise Control Area]{.underline}: An area in which noise is 85 dBA
    or greater. This designation is independent of duration.

23. [Octave Band Analysis]{.underline}: An analysis of the standard
    frequency ranges (31.5 Hz ‑ 16k Hz) used to characterize noise. The
    frequency of each band is such that the upper band limit is twice
    the lower band limit. Octave band analysis is often used as a means
    to determine materials and methods used for controlling noise.

24. [Otitis media]{.underline}: Infection and inflammation of the middle
    ear space and ear drum.

25. [Otitis externa]{.underline}: Infection and inflammation of the
    external ear canal.

26. [Otolaryngologist]{.underline}: Physician specializing in diagnosis
    and treatment of disorder of the ear, nose, and throat.

27. [Representative Exposure]{.underline}: Measurement of an employee\'s
    noise dose or 8‑hour time weighted average (8-hr TWA) noise exposure
    that is representative of the exposure of other employees in that
    work area or job classification.

28. [Standard Threshold Shift (STS)]{.underline}: An average hearing
    threshold shift of 10 dB or more at 2000, 3000, and 4000 Hz; in
    either ear relative to the baseline audiogram or to the most recent
    audiogram which has established a standard threshold shift. A
    threshold shift can be either temporary or permanent. A temporary
    threshold shift is a change in hearing threshold, primarily due to
    exposure to high intensity noise that can usually recover in 14 to
    72 hours away from noise exposure. Any loss remaining after an
    adequate recovery period is termed a permanent threshold shift.

29. [Sound Level]{.underline}: Mathematically equivalent to ten times
    the common logarithm of the ratio or the square of the measured
    A‑weighted sound pressure to the Standard reference pressure of 20
    micropascals (measured in decibels).

30. [Sound-level meter]{.underline}: Electronic instrument for the
    measurement of sound level.

31. [Time‑Weighted‑Average (8-hr TWA)]{.underline}: Sound level which,
    if constant over an 8‑hour workday exposure, would result in the
    same noise dose as is measured.

32. [Tinnitus]{.underline}: A noise in the ears, as ringing, buzzing,
    roaring, clicking, etc.