Occupational Health & Safety Hearing Conservation Program

Reference Materials


Environmental Health and Safety Office
















1.0  Introduction

     The University of Hawaii is committed to providing a safe 
     and healthful environment for all employees.  Consistent
     with this committment, we have developed a Hearing Conser-
     vation Program.

     This program is designed to provide the maximum protection 
     for all employees who may be exposed to high noise levels
     as well as to ensure compliance with the State of Hawaii,
     Occupational Safety and Health Standards.

     In addition, guidelines are provided for the selection, use
     and purchase of hearing protectors that will adequately
     protect all employees who may be exposed to high noise 

     This written program is available for review by any inte-
     rested employee or representative of any employee.  Any
     questions about this program should be addressed to the
     EHSO.  This program is monitored and audited by the EHSO
     to ensure that the policies are carried out and that the
     program is effective.

2.0  Progam Administration 

     Each supervisor shall be responsible for implementing the
     provisions of this program.  All training requirements under
     this program shall be provided at no cost to the employee.

     The Industrial Hygienist from the UHM Environmental Health
     and Safety Office shall assist the departments with the 
     implementation and maintenence of the Hearing Conservation

3.0  General Requirements

     When employees are exposed to sound levels exceeding those 
     in Appendix A, administrative or engineering controls shall
     be utilized.  If administrative or engineering controls are
     not available, personal protective equipment shall be used
     to reduce the sound levels to that in Appendix A or lower.

     Exposure to impact or impulse noise shall not exceed 140 dBA
     peak sound pressure level.  If the variations in peak of 
     sound pressure levels are one second or less, the noise is
     to be considered continuous.

     All employees whose noise exposure equals or exceed an 8-
     hour time weighted average (TWA) of 85 dBA slow response,
     shall be included in this program and are subject to all 
     elements in Sections 4.0 through 9.0.  This level shall be
     computed without regard to attenuation factors provided by 
     the use of personal protective equipment.
4.0  Monitoring

     A monitoring strategy shall be developed to identify those
     workareas with a sound pressure level of 85 dBA slow res-
     ponse or greater.  This monitor strategy shall be designed
     to identify all employees to be covered by this program and 
     to enable them to select the proper hearing protectors.

     Monitoring shall be conducted whenever a change in produc-
     tion, process, equipment, or controls may cause an increase
     in sound pressure levels so that the additional employees 
     are effected or the attenuation provided by the hearing
     protection may become ineffective.

     After the completion of monitoring, all employees exposed to
     a time weighted average of 85 dBA or greater shall be noti-
     fied of the results.

     Affected employees or their representatives will be allowed 
     to observe all noise measurements taken for compliance with 
     this program.

     All instruments used to measure sound levels and employee 
     noise exposure shall be calibrated to ensure accuracy with         
     a tolerance of no more than +/- 2 dB.

5.0  Audiometric Testing Program

     An audiometric examination shall be provided to employees
     whose noise exposure equals a time weighted average of 85 
     dBA or greater at no cost to the employee.  The audiometric
     test shall be conducted by a licensed or certified audio-
     logist, otolaryngologist, or another physician, or by a 
     technician who is certified by the Council of Accreditation
     in Occupational Hearing Conservation (CAOHC).

     Within 6 months of an employee's first exposure to sound
     levels of 85 dBA slow response or greater, a baseline audio-
     gram shall be taken against which subsequent audiograms may 
     be compared.

     Baseline audiograms must be preceded by 14 hours without 
     exposure to workplace noise.  Hearing protectors may be used
     as a substitute for the requirement that baseline audiograms
     be preceded by 14 hours without exposure to workplace noise.

     The employee shall endeavor to avoid high levels of non-
     occupational noise 14 hours before the audiometric examina-

     Where baseline audiograms are given more than 6 months after
     an employee's initial exposure, the employee shall wear 
     hearing protectors until the baseline audiogram is obtained.

     After a baseline audiogram has been taken, each employee 
     exposed to noise at the 85 dBA time weighted average level
     or above shall have an annual examination.

6.0  Audiometric Examination Evaluation

     Each employee's audiogram shall be compared with their
     baseline audiogram to determine if the audiogram is valid
     and if a standard threshold shift has occurred.

     A standard threshold shift is defined as a change in the 
     hearing threshold of an average of 10 decibels or more at
     2000, 3000 and 4000 hertz in either ear when compared to
     the original audiogram.

     If a standard threshold shift has occurred, the employee
     may be retested within 30 days and the results of the retest
     may be considered the annual audiogram.

     A physician, audiologist, or otolaryngologist shall review 
     the problem audiograms and determine if there is a need for 
     further evaluation.

     The employee shall be notified in writing within 21 days of
     the determination of a standard threshold shift.

     Unless a physician determines that the standard threshold
     shift is not work related or aggravated by occupational 
     noise exposure, the following steps will be taken upon dis-
     covering a standard threshold shift:

          A.  employees not using hearing protectors shall be 
              fitted with hearing protectors, trained in their
              use, and required to use them;
          B.  those employees already using hearing protectors
              shall be refitted with protectors offering greater
              attenuation if necessary and retained in their use;

          C.  the employee shall be referred for a clinical 
              examination or evaluation if the use of hearing 
              protectors causes or aggravates a medical pathology
              of the ear; and

          D.  the employee shall be informed of the need for an
              otological examination if the medical pathology of
              the ear is unrelated to the use of hearing protec-

      The employee shall be informed if subsequent audiometric
      testing indicates that the standard threshold shift is not
      persistent.  If the employee works in areas subject to a
      time weighted average of less than 90 decibels, the re-
      quired use of hearing protectors may be discontinued.
      An annual audiogram shall be substituted for the baseline
      audiogram when the standard threshold shift is determined
      to be persistent by the audiologist, otolaryngologist, or

      An annual audiogram shall also be substituted for the base-
      line audiogram when it shows significant improvement over
      the baseline.

7.0   Hearing Protectors 

      Hearing protectors shall be made available and shall be 
      worn by all employees exposed to an 8-hour time weighted
      average of 85 dBA or greater. This includes those employees
      who have experiences a standard threshold shift and those 
      who have not yet had a baseline audiogram.

      Each employee required to use hearing protectors shall 
      select the protector from a variety of hearing protectors 
      provided and shall be properly fitted.

      The protector selected must provide attenuation to at least
      an 8-hour time weighted average of 90 dBA.

      For those employees who have experienced a standard thres-
      hold shift, the attenuation shall be at least an 8-hour 
      time weighted average of 85 dBA or below.

8.0   Training     

      All employees exposed to noise at a time weighted average
      of 85 dBA or greater shall participate in a hearing conser-
      vation training program that shall include:

           A.  the effects of noise upon hearing

           B.  the fitting, use, care, and purpose of hearing
               protectors; and
           C.  the purpose of audiometric testing and an explana-
               tion of the test procedures

     This training program shall be repeated annually for all 
     employees included in the Hearing Conservation Program.

9.0  Recordkeeping     

     Each supervisor shall maintain an accurate record of all 
     employee exposure measurements required by section 4.0.

          A.  Audiometric Tests

              The employer shall retain all employee audiometric
              test records.  This record shall include:
              -  Name and job classification of the employee;
              -  Date of the audiogram;

              -  The examiner's name;

              -  Date of the last acoustic or exhaustive
                 calibration of the audiometer; and

              -  Employee's most recent noise exposure assessment

          B.  Each supervisor shall retain accurate records of 
              the measurements of the background sound pressure 
              levels in audiometric test rooms.

          C.  Each supervisor shall retain records required in 
              this section for at least the following periods.

              -  Noise exposure measurement records shall be
                 retained for 2 years.

              -  Audiometric test records shall be retained for
                 the duration of the affected employee's employ-

          D.  All records required in this section shall be 
              available upon request to employees, former 
              employees, representatives designated by the 
              individual employee, and representatives of the
              Hawaii Division of Occupational Safety and Health.

          E.  Each supervisor shall transfer to his successor all
              records required to be maintained by this section,                 
and the successor shall retain them for the remain-
              der of the period prescribed in (D) above.



        Duration                             Sound Level
        Per Day                              dBA Slow
        Hours                                Response

          8 ...................................90

          6 ...................................92

          4 ...................................95

          3 ...................................97

          2 ..................................100

          1.5 ................................102

          1.0 ................................105

          0.5 ................................110

          0.25 (or less) .....................115

*When the daily noise exposure is composed of 2 or more periods     
of noise exposure of different levels, their combined effect 
 shall be considered, rather than the individual effect of each.
 If the sum of these fractions: C/T + C/T + ... C/T exceeds 
 unity, then the mixed exposure shall be considered to exceed the   

 "C" indicates the total time of exposure at a specified noise
  level, and "T" indicates the total time of exposure permitted 
  at that level.

  Exposure to impulsive or impact noise shall not exceed 140 dB
  peak sound pressure level.


Maximum Allowable Octave Band Sound Pressure Levels For   
	Audiometric Test Rooms*

      Octave Band Center
      Frequency (Hz) .... 500    1000    2000    4000    8000

      Sound Pressure
      Level (dB) ........  40      40      47      57      62

     *Rooms used for audiometric testing shall not have back-
      ground sound pressure levels exceeding those above when
      measured by equipment conforming at least to the type 2
      requirements of ANSI S1.4 and to the Class II requirements
      of ANSI S1.11.



Ear Muffs

Ear muffs come in many styles.  Most are attached to spring-loaded 
headbands, while others are attached directly to safety headgear.  
Specialized muffs are also available for persons who work in high 
voltage exposures, or who need to filter out hazardous noises 
while retaining acute hearing for normal sound ranges.  Muffs 
cover the entire ear and can reduce noise by as much as 15-30 
decibels.  (Muffs are often used in conjunction with ear plugs 
when a worker is exposed to extremely high noise levels - 105 
decibels and above.)

Ear Plugs 

Like muffs, ear plugs come in many varieties-formable, custom 
molded, pre-molded, disposable, reusable-and may be made of 
different types of materials such as acoustical fiber, silicone,
rubber, or plastic.  Ear plugs are positioned in the outer part 
and may reduce noise by as much as 30 decibels.

Canal Caps

These hearing prtoectors cap off or close the ear canal at its 
opening.  Like many muffs, canal caps are connected to a flexible
headband that ensures a close fit.  Canal caps are most commonly 
used when an individual is unable to use traditional ear plugs.



2305 Kamehameha Hwy.
P.O. Box 30707
Honolulu, Hawaii 96820
Telephone: 842-2222

302 Mokauea Street
Honolulu, Hawaii 96819
Telephone: 847-4017