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					                  Occupational Health Unit
        Noise and Audiometric Surveillance Procedure
Purpose

To provide a procedure for audiometric testing that establishes quantitative baseline
hearing levels and subsequently monitors and protects identified personnel who may be
adversely affected by exposure to noise levels at work. Periodic audiometric testing
assists in determining the effectiveness of the controls adopted by the company as part of
the hearing conservation programme. The procedure enables the company to comply with
legislation and reflects evidence-based practice.

Scope

This procedure applies to all University of Edinburgh employees and individuals who utilise
the Occupational Health Service.

Standard

In line with the Health and Safety at Work etc Act 1974 and the Management of Health and
Safety at Work Regulations, employers have a duty of care for the health, safety and
welfare of their employees.

Regulation 6 of the Management of Health and Safety at Work Regulations states that
“Every employer shall ensure that his employees are provided with such health
surveillance as is appropriate having regards to the risks to their health and safety which
are identified by the assessment. “

The Control of Noise at Work Regulations 2005 specifically requires employers to: -

   •    Conduct a suitable and sufficient noise risk assessment where employees are
        exposed at or above the lower exposure action value or exposure limit value.
   •    Eliminate noise at source or, where this is not reasonably practicable, reduce to
        noise to as low a level as is reasonably practicable.
   •    Make suitable hearing protection available on request to employees exposed to
        noise between the lower and upper exposure action values.
   •    Provide suitable hearing protection for employees and ensure they wear them
        correctly when noise exposures exceed the upper exposure action values.
   •    Clearly demarcate, designate and restrict access to work areas where the noise
        levels remain at or above the upper exposure action value.
   •    Provide suitable health surveillance for employees who are or are liable to be
        exposed to noise.
   •    Provide information, instruction and training.
                 Occupational Health Unit
       Noise and Audiometric Surveillance Procedure
Regulation 4 outlines the exposure limit values and action values as being: -

     1. Lower exposure action values (lower of the 2 levels of daily or weekly noise exposure or of
         peak sound pressure which if reached or exceeded, require specified action as above to be taken
         to reduce risks)
            (a) Daily or weekly personal noise exposure of 80dB(A)
            (b) Peak sound pressure of 135dB(C)
                (Maximum sound pressure to which an employee is exposed to)

     2. Upper exposure action values (higher of the 2 levels of daily or weekly noise exposure or
         peak sound pressure which if reached or exceeded require specified action as above to be taken
         to reduce risk)
            (a) Daily or weekly personal noise exposure of 85dB(A)
            (b) Peak sound pressure of 137dB(C)

     3. Exposure limit values (the level of daily or weekly personal noise exposure or of peak sound
         pressure that must not be exceeded)
            (a) Daily or weekly personal noise exposure of 87dB(A)
            (b) Peak sound pressure of 140dB(C)

The wearing of ear protection is mandatory at 85dB(A) and above.

The OHNA / OHSN is required to: -

      Where noise risk assessment and occupational hygiene reports have indicated
      measured noise levels that require health surveillance, consult with the appropriate
      managers to obtain confirmation of the work areas and processes.

      Provide health surveillance to noise exposed employees who -
      - are exposed at or above the upper action value of 85dB(A) or peak sound
        pressure of 137dB(C)
      - have been identified as being at specific risk from exposure to noise levels at or
        above the lower action value of 80dB(A) or peak sound pressure of 135dB(C)

      Send a health surveillance appointment letter to the employee advising of date and
      time.

      A copy of this letter will be kept in the employee’s health surveillance record.

      Inform employee of outcome of health surveillance and determine fitness to
      continue in current role.

      Provide information by providing employee with a copy of Protect Your Hearing or
      Lose it, INDG363 (rev1) after every appointment.


      Arrange follow-up investigations if required.
                 Occupational Health Unit
       Noise and Audiometric Surveillance Procedure
       Report the outcome of health surveillance to the appropriate manager within the
       bounds of medical confidentiality.

       Input the assessment results into OPAS enabling the OHP to analyse trends and
       produce robust data when requested by the business. This assists in periodically
       determining the effectiveness of risk control measures.

The OH Physician is required to: -

       Where all appropriate surveillance and referral has been carried out, confirm
       diagnosis of Noise Induced Hearing Loss.

Procedure

To comply with the requirements of The Control of Noise at Work Regulations 2005,
guidance states, “if risk assessment indicates that there is a risk to health”. Regulation 9
(1) requires employers to provide suitable health surveillance where there is a risk from
exposure to noise without taking account of the noise reduction provided by hearing
protection.

The health surveillance will be carried out by an OHNA/OHSN or other competent person
in Occupational Health under the direction of a suitably qualified person. In addition to
knowledge of the effects of noise and the technical aspects of audiometric testing, the
competent person must be fully conversant with the types of hearing protection used on
their sites to be able to advise employees of its correct use and maintenance

Initial or Baseline Noise and Audiometric Health Surveillance

Audiometry questionnaire will be completed and an audiometric test carried out: -

      At pre-employment or within 12 weeks of commencement for new employees to a
      role where they are or may be exposed to noise at or above the upper action value
      of 85dB(A) or peak sound pressure of 137dB(C) or have been identified as being at
      specific risk from exposure to noise levels at or above the lower action value of
      80dB(A) or peak sound pressure of 135dB(C).

       Prior to beginning work or within 12 weeks for employees transferring to a new role
       within the University where they are or may be exposed to noise at or above the
       upper action value of 85dB(A) or peak sound pressure of 137dB(C) or have been
       identified as being at specific risk from exposure to noise levels at or above the
       lower action value of 80dB(A) or peak sound pressure of 135dB(C)
                 Occupational Health Unit
       Noise and Audiometric Surveillance Procedure
Review Health Surveillance

      Annually for first 2 years completing questionnaire and carrying out audiometric
      test.

      Thereafter 3 yearly completing questionnaire and carrying out an audiometric test.

      More frequent monitoring may be required depending on outcome of individual
      assessment.

The OHNA / OHSN should either: -

Where an employee falls within Category 1, using HSE Categorisation Scheme: -

      Give formal notification of fitness.

Where an employee falls within Category 2, using HSE Categorisation Scheme: -

      Give employee formal notification of hearing damage and advise on how to
      minimise or prevent further damage.

Where an employee falls within Category 3 and 4 or has a unilateral hearing loss on
initial assessment, or where there has been a change from their last audiogram, using
HSE Categorisation Scheme: -

      With employee consent refer the employee to their General Practitioner with a copy
      of employee’s audiogram to inform GP of hearing damage and / or advise follow up
      if required.

      The OHNA / OHSN should advise employee to seek appointment with GP to
      discuss next steps and whether further referral to ENT specialist is required.

      Obtain consent from the employee to allow his / her GP to provide a medical report
      of follow up action / advice given by GP or specialist within 1 year of initial referral.

      Those employees who have consistent Category 3, 4 and / or unilateral results,
      that have been fully investigated by employee’s GP and / or specialist require their
      GP to be informed of ongoing category and no advice for follow up is required.

      Where there has been a significant change in hearing loss, further referral would be
      required.

      Make a direct referral to the OH Physician (OHP) only where: -

         - first result as Category 3 or 4
         - condition is deteriorating
                 Occupational Health Unit
       Noise and Audiometric Surveillance Procedure
Notification and Recording of Results

      At each assessment the employee will be informed of their results verbally by the
      competent person and advised when they require review or further follow up by
      OHP or own GP. The employee is asked to sign the audiometry questionnaire to
      acknowledge his / her understanding of the results.

      The HSE pocket card, INDG363 (Rev1) Protect Your Hearing or Lose It! should be
      given to all employees for the provision of Information on the consequences of
      exposure to noise and use of PPE provided by employer.

      Managers will be notified of the employee’s fitness for role using Certificate of
      Fitness Form.

      Where the employee is considered by the OH Physician to be unfit for such work,
      the manager will be informed and suitable work adjustments or alternative work will
      be discussed in conjunction with the employee.

      Following every assessment the Health Surveillance Record must be updated. This
      record is not deemed to be confidential in nature and can be viewed by managers
      and external bodies for the purpose of audit or inspection. The outcome of the
      audiometric assessment will be noted as fit or unfit.

      On completion of the assessment, the appropriate results and recall interval will be
      entered onto OPAS system.

Non-attendance for Health Surveillance

If the employee fails to attend a second appointment a DNA letter will be sent to the
employee’s manager. A recall date of 1 year will be entered onto OPAS to ensure
Occupational Health continue to provide an annual appointment. Copies of the
appointment letters must be stored in employee’s health surveillance record.

Exit Health Surveillance

      Where an employee moves to another role with no further exposure to noise.

      Prior to leaving the company for employees who have been subject to the
      company’s hearing conservation programme, if not carried out within the last 6
      months.

      Health surveillance results require to be maintained for 40 years following the end
      of employment.
                  Occupational Health Unit
        Noise and Audiometric Surveillance Procedure
Conducting the Audiometric Programme

To ensure consistency of results: -

        Audiometric testing should be conducted in an acoustic booth where the ambient
        noise does not exceed 35dB(A) from BS ISO 8253-1, using a pure tone audiometer
        and supra – aural earphones.

        Where a booth is not available, the testing room should be sited away from sources
        of noise, such as toilets, traffic, office areas, etc. Noise can be measured to ensure
        noise levels do not exceed 35dB. Reference should be made to EN 26189.

Annual and Daily Equipment Checks

Annual

        Check with ASRA engineer whether they can carry out octave band analysis of
        noise levels within the acoustic booth.

        Calibration of Pure Tone Audiometer and earphones by ASRA Engineer on site.

Daily

        Straighten any tangled leads and ensure all connections are firm and giving good
        contact.


        Check all knobs and switches are secure and function in a silent, smooth and click-
        free manner.

        Check the function response button.

        Check tension of the earphone headband.

        Ensure audiometer and attachments are clean. Do not use alcohol wipes to clean
        earphones, alcohol free wipes will be suitable and sufficient.

        An approximate calibration check can be made using the acoustic ear by carrying
        out a functional test of the pure tone audiometer.
        The hearing level must be accurate to within plus or minus 3dB from 500Hz to 4kHz
        and to within plus or minus 5dB at the remaining frequencies.

The University has elected to maintain calibration records to confirm the validity of test
results for 40 years.
                Occupational Health Unit
      Noise and Audiometric Surveillance Procedure
Preparation of Subject

      Careful explanation of the procedure should be given to the employee prior to
      commencing tests.

      Audiometric testing will ideally be carried out when an employee has been free of
      noise for a period of at least 16 hours, ideally pre - shift, to eliminate the potential
      effects of temporary threshold shift.

      If this is not possible, then testing should be arranged for the beginning of the
      working shift and if audio result is unsatisfactory then should be carried out pre -
      shift.

      If the employee has been working in a designated ear protection zone and has
      been wearing suitable hearing protection for the duration of that work, audiometry
      can be carried out but details of potential noise exposure will be recorded on the
      health surveillance form.

      Where the employee is experiencing symptoms of an upper respiratory tract or ear
      infection the audiometric test should be postponed until the employee is fully
      recovered.

      The audiometry questionnaire will be completed by the employee with assistance
      where required by the OHNA / OHSN or competent person.

      Prior to testing, the ear canal and tympanic membrane will be visually inspected
      using an otoscope. Any abnormalities, excessive wax or exudates should be noted
      on the form. In the event that excessive wax appears to be occluding the ear
      canal, advice should be given regarding softening of wax and ear syringing prior to
      completing the audiometric test.

      On completion of the test the OHNA / OHSN or other competent person will
      evaluate the audiometric results by calculations of hearing levels at several
      different groups of frequencies.

      The sum of 1, 2, 3, 4 and 6kHz frequencies will be calculated for each ear and
      compared with the warning and referral levels related to age and sex as shown in
      the chart below.

         (a) If the sum of both ears is below the warning level then the individual will
             fall into Category 1 – Acceptable Hearing Ability

         (b) If the sum for either ear exceeds or is equal to the warning threshold
             level for their respective age and gender then the individual will fall into
             Category 2 – Mild Hearing Impairment.
             Occupational Health Unit
   Noise and Audiometric Surveillance Procedure
     (c) If the sum exceeds or is equal to the referral level for either ear then the
         individual will fall into Category 3 – Poor Hearing and would require referral
         for further medical advice.
                 SUM OF HEARING LEVELS 1,2,3,4 and 6kHz

                    Males                             Females

    Age in       Warning     Referral                Warning      Referral
    years         level       level                   level        level

    18-24          51         95                        46          78
    25-29          67         113                       55          91
    30-34          82         132                       63          105
    35-39         100         154                       71          119
    40-44         121         183                       80          134
    45-49         142         211                      93           153
    50-54          165         240                     111          176
    55-59         190          269                     131           204
    60-64         217         296                      157           235
    65             235        311                      175          255



  To determine whether there has been a rapid loss in hearing since the last
  examination, a sum of the hearing thresholds obtained at 3, 4 and 6kHz should be
  made. If the previous test was performed within the last 3 years and an increase in
  hearing threshold level of 30dB or more (as a sum of 3, 4 and 6 kHz) is found,
  then this individual would fall into Category 4 – Rapid Hearing Loss and require
  referral on for further medical advice.

  A further sum should be undertaken to determine whether an individual has a
  unilateral hearing loss suggesting a problem due to disease or infection, sum of
  hearing levels 1, 2, 3 and 4kHz for both ears. If the difference between the ears
  is greater than 40dB, the individual should be advised of the findings and referred
  for further medical advice.

  Where an audiometric test indicated a conductive hearing loss and visual inspection
  of the auditory canal had highlighted a significant amount of wax, the employee will
  be given advice on the softening and removal of wax. Following the successful
  removal of wax and a 14 day period of adjustment, a further audiometric test will be
  carried out.

  As a quality control measure, any audiogram which when compared with the
  previous results shows a shift of 10dB or more at any frequency should be
  repeated.

The audiogram will then be classified in accordance with the HSE criteria as below
                 Occupational Health Unit
       Noise and Audiometric Surveillance Procedure

       Category        Symptom                                       Action
          1            Hearing within normal limits                  None

            2          Mild hearing impairment                       Warning
                       Hearing level normally experienced by 1 in
                       4 persons. May indicate developing Noise
                       Induced Hearing Loss

            3          Poor hearing                                  Referral
                       Hearing level normally experienced by 1 in
                       10 persons. Suggests significant Noise
                       Induced Hearing Loss

            4          Rapid hearing loss                            Referral
                       Reduction in hearing level of 30dB or more
                       within 3 years or less - could be caused by
                       noise exposure or disease


Criteria For Fitness

The normal parameters: -

      No significant positive answers to the audiometry health assessment questionnaire.
      The OHNA will use his / her knowledge and initiative in deciding which answers
      may be significant.

      No abnormalities detected in the external auditory meatus and tympanic membrane
      or no new abnormalities since the previous examination.

      Where there is a significant concern in relation to the information provided by
      questionnaire or visual inspection of the auditory canal, the OHNA should discuss
      the results with the OHP who may pass the individual as fit or request a further
      consultation.

      Audiogram results within the normal limits for age and sex or no significant change
      since the previous audiogram.

      Where the audiogram result is within the normal parameters, the OHNA may pass
      the employee as fit to continue working in ear protection zones.

      Employees with an audiogram result falling into the warning Category 2 will have
      their results explained and the importance of wearing appropriate hearing protection
      correctly will be emphasised and will be passed fit to continue to work in ear
      protection zones.
                 Occupational Health Unit
       Noise and Audiometric Surveillance Procedure
      Where a new audiometry result corresponds with HSE Categories 3 and 4, the
      OHNA will provide a letter of referral and a copy of the most recent audiogram to
      the employee’s GP. Whilst awaiting feedback, employee will be passed fit to
      continue working in ear protection zone with significant emphasis being placed on
      the wearing of hearing protection provided by employer.

      If the employee’s audiometry result remains within the referral Categories 3 and 4
      year on year but with no change and further referral outcomes are recorded in
      employees health record, no follow up is required and review is arranged.
      Employee will be passed fit to continue working in ear protection zone.

      Where audiometry results show a unilateral hearing loss, the employee is informed
      of this and referred for further medical opinion and is passed fit to continue working
      in ear protection zone with emphasis on the use of provided hearing protection.

      If noise induced hearing loss is identified but, following referral, is deemed to be
      stable, continuing exposure to noise will usually be acceptable where hearing
      protection is assessed to be adequate and is strictly worn.

      There may be cases where the affected employee has responsibility for safety and
      needs to hear auditory warning signals or where the risk of further hearing loss is
      unacceptable despite hearing conservation controls and appropriate PPE. In such
      cases the OHP will make the decision on the employee’s fitness for his current
      employment and provide advice to the manager regarding suitable redeployment
      options.

References

Health and Safety at Work etc Act 1974
Management of Health and Safety at Work Regulations 1999
Control of Noise at Work Regulations 2005
HSE Guidance Note MS 26 - A guide to audiometric testing programmes
British Society of Audiology. Recommended procedure for pure-tone bone conduction
threshold audiometry with and without masking and determination of uncomfortable
loudness levels. Br J Audiol, 2004.
British Standard Institution BS EN ISO 8253-1:1998 Acoustics. Audiometric test
methods – Part 1: Basic pure tone air and bone conduction threshold audiometry identical
to ISO8253 –1: 1981.
EN 26189

Appendices

Appendix 1 – Noise and Audiometric Surveillance Flowchart
Appendix 2 - ASRA Normal Test Sequence
                   Occupational Health Unit
         Noise and Audiometric Surveillance Procedure
Noise and Audiometric Surveillance Flowchart

                                          Baseline audiometric test
                                          where noise assessed as a
                                         hazard (pre-employment and
                                               pre-placement)


                 Category 1 - normal result                       Abnormal result



  Annual audiometric
  test for first 2 years




                                                                      Results reviewed by
   Normal result                      Abnormal result                 OHNA and / or OHP




 3 yearly audiometric
        testing




 Employee advised of
 normal result. Repeat
 audiogram in 3 years


                                       Category 2 – Mild        Category 3 – 4 Poor            Unilateral
                                      Hearing Impairment         Hearing – Rapid            Hearing Loss
                                       Employee formally           Hearing Loss                Indicating
                                     warned of audiometry       Employee referred to            possible
                                     result and importance              GP.                   infection or
                                     of wearing appropriate      Result recorded in             disease.
                                       hearing protection             OPAS.                    Employee
                                           re-iterated.                                     referred to GP.




                                                              Repeat audiogram in 1 year
                 Occupational Health Unit
       Noise and Audiometric Surveillance Procedure
ASRA Normal Test Sequence

				
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