Chapter Outline
Acts involved in occupational audiometric testing | SANS Standards related to audiometry |
Regulations pertaining to audiometry |
Educational Aims
After studying this chapter, you should be able to:
Identify the different legislative requirements for occupational audiometryKey Terms / Abbreviations
Abbreviation | Meaning |
≤ | This symbol means equal to or less than |
≥ | This symbol means equal to or greater than |
CC | Compensation Commissioner |
COP | Code of Practice |
DMRE | Department of Mineral Resources and Energy |
NIHL | Noise-induced hearing loss |
NRL | Noise Rating Level |
PD | Permanent Disability |
PLH | Percentage Loss of Hearing |
SABS | South African Bureau of Standards |
SANS | South African National Standard |
STS | Standard Threshold Shift |
Term | Explanation |
8-Hour Rating Level | The rating level normalised to a nominal 8-hour working day as indicated in SABS 083. In South Africa, the criterion for reducing the risk of hearing damage is based on limiting the exposure to an 8-hour rating level (Lreq8h) of 85dB (A). |
Approved Noise Inspection Authority | An approved inspection authority means a DOL approved provider for the monitoring of noise in the workplace. |
Attenuation of Hearing Protectors | Attenuation is “the reduction in sound pressure level incident upon the ear due to the application of a hearing protector or, specifically, the change in hearing threshold level that results when a hearing protector is worn.” Hearing protectors must have a proven capability of reducing the sound exposure to which the wearer is exposed. |
Audiometric Zero | Audiometric Zero simply means the threshold of hearing. It is the lowest intensity at which a normal person can hear a sound. The audiometric zero varies from person to person. Thus, the International Standards Organization (ISO) has defined it as “audiometric zero is the mean value of minimal audible intensity in a group of normally hearing healthy young adults.’’ Audiometric zero is measured at the milestone baseline test. |
Compensation Commissioner | The Compensation Commissioner (CC) is appointed under section 2(1)(a) of the Compensation for Occupational Injuries and Diseases Act, 1993 (Act 130 of 1993); one of the responsibilities of the CC is to determine the validity of a claim, determine the degree of disability and payment of compensation to the claimant. |
Competent Person | (a) a person registered in terms of the Health Professions Act, 1974 (Act 56 of 1974), with the Health Professions Council of South Africa in any of the following three categories— (i) Otorhinolaryngologist (ear, nose, and throat specialist); (ii) speech therapist and audiologist; or (iii) occupational medicine practitioner; or (b) a person with a qualification in audiometric techniques obtained from an institution registered with the South African Qualification Authority or any of its structures in terms of the South African Qualifications Authority Act, 1995 (Act 58 of 1995), and registered with the South African Society for Occupational Health Nursing (SASOHN) |
Equivalent Continuous Rating Level | The Equivalent Continuous Sound Pressure Level, or Leq/LAeq, is the constant noise level that would result in the same total sound energy being produced over a given period. LAeq is a fundamental measurement parameter designed to represent a varying sound source over a given time as a single number. |
Occupational Hygiene | Workers are exposed to a wide range of health and safety hazards in the workplace environment. These hazards can result in either acute or chronic health effects depending on nature and route of exposure. Occupational hygiene plays a vital role in alleviating exposure to harmful substances and agents in the workplace. The components of occupational hygiene are identification, evaluation, and control of workplace health hazards. The most important aspect of occupational hygiene is the control of hazards. However, identification and evaluation are necessary steps leading to the implementation of appropriate and cost-effective control measures. |
Mandatory Code of Practice | A code of practice is a document that complements occupational health and safety laws and regulations to provide detailed practical guidance on how to comply with legal obligations. They should be followed unless another solution with the same or better health and safety standard is in place. When published the DME all mining companies are required to implement them. If mentioned in an Act they are also mandatory. |
Medical Surveillance | A planned program to monitor the health of workers and is permissible in terms of legislation and justifiable in terms of medical evidence, conditions of employment and the inherent requirements of the job. |
Milestone Baseline | The initial audiometric value was determined at the first STS testing. A milestone baseline audiogram is the better of the employee's two audiograms performed by an audiometrist on the same day and that do not differ from each other by more than 10dB for any of the frequencies in the 2000, 3000, and 4000 hertz (Hz) test ranges in one or both ears. |
Noise Assessment | A noise survey is conducted in areas where noise exposure is likely to be hazardous. Noise level refers to the level of sound. A noise survey involves measuring noise levels at selected locations throughout an entire plant or sections to identify noisy areas. This is usually done with a sound level meter (SLM). Therefore, a noise assessment Is a programme to determine any risk from exposure to noise associated with the workplace to identify the steps that need to be taken to remove, reduce or control such hazards. |
Noise-Induced Hearing Loss | Noise-induced hearing loss begins at the higher frequencies (3000 to 6000Hz) and develops gradually as a result of chronic exposure to sound levels equal to or above 85dB(A) (continuous exposure to loud noise over an extended period, such as noise generated in an engineering workshop). Although the loss is typically symmetric, noise from firearms or sirens may produce an asymmetric loss. NIHL can even be caused by a one-time exposure to an intense “impulse” sound, such as an explosion often leading to acoustic trauma. Recreational activities can also cause NIHL such as target shooting and hunting, listening to MP3 players at high volume through earbuds or headphones, playing in a band, and attending loud concerts. NIHL is 100% preventable. |
Noise Rating Limit | The value of the 8-hour rating level, 85dB(A) at and above which hearing impairment is likely to result. |
Percentage Loss of Hearing | Percentage Loss of Hearing (PLH) is a reference value for the hearing status of an individual against which loss can be measured however PLH does not necessarily indicate hearing loss. Instruction 171 introduced a measure of impairment termed percentage loss of hearing (PLH) which is calculated by using a series of tables based on a summation of hearing loss in each ear at the following frequencies: 500, 1000, 2000, 3000 and 4000Hz (COIDA, 2001). The PLH forms the principal criterion for assessing hearing status for compensation claims. |
SABS / SANS Explanatory Note | “SABS” is a certification body that is accredited by SANS. It is therefore incorrect to refer to the SABS as a standard, as it is a testing and certification body that is allowed to sample and test products and certify a producer’s product to a specific SANS standard, through their SANS accreditation. “SANS”, on the other hand, refers to a standard that specifies the performance requirements of a specific product. A SANS standard may be either locally written or created by adopting an international (usually ISO) standard. |
Standard Threshold Shift | An average change in hearing of 10dB or more at the frequencies of 2000Hz. 3000Hz and 4000Hz in one or both ears, as compared to the employee's milestone baseline audiogram. |
STS Reportable Level | The STS that is reported in terms of milestone monitoring is the average change in hearing from 'audiometric zero'. Note i.e., milestone baseline STS, is 25dB hearing loss or greater at the same frequencies in the same ear. |
The Risk Employees / Safety-Critical Employees | Employees exposed to noise levels above or equal to the occupational exposure limit |
Legislations / Regulations and SANS Standards
Item | Explanation |
NIHL Regulations | Noise-Induced Hearing Loss Regulations, GoN 307, G24967 (updated 7 March 2003) |
EEA | Employment Equity Act, No 55 of 1998 |
MHS Act | The Mine Health and Safety Act, No 29 of 19967 |
Regulation 839 | Guidance Note for the Implementation of Standard Threshold Shift in Medical Surveillance of Noise-Induced Hearing Loss (Mining only) |
OHS Act | The Occupational Health and Safety Act, No 85 of 19936 |
General Administrative Regulations | The General Administrative Regulations in terms of Occupational Health and Safety Act, 1993 (Act No. 85 of 1993), Government Notice R.1449 of 6 September 1996; |
COID Act | The Compensation for Occupational Injury and Disease Act, No 130 of 1993 |
Instruction 171 | Circular Instruction 171 plus the supplement (found inside COID Act) – May 2001 means the Compensation Commissioner’s Circular Instruction No.171 and Supplement entitled Determination of Permanent Disablement Resulting from Noise-Induced Hearing Loss and Trauma |
SANS 10083: 2013 | The Measurement and Assessment of Occupational Noise for Hearing Conservation Purposes https://store.sabs.co.za/catalog/product/view/id/217774/s/sans-10083-2013-ed-5-02/ |
SANS 10182: 2006 | The Measurement and Assessment of Acoustic Environments for Audiometric Tests https://store.sabs.co.za/catalog/product/view/id/219023/s/sans-10182-2006-ed-2-02/ |
SANS 10154-1: 2012 | The Calibration of Pure-Tone Audiometers Part 1: Air Conduction https://store.sabs.co.za/catalog/product/view/id/218840/s/sans-10154-1-2012-ed-1-03/ |
SANS 8253-1: 2011 | Audiometric Test Methods Part 1: Pure Tone and Bone Conduction https://store.sabs.co.za/catalog/product/view/id/216804/s/sans-8253-1-2011-ed-2-00/ |
SANS 50458: 2008 | Hearing Protectors – Recommendations for the Selection, Use, Care and Maintenance – Guidance Document https://store.sabs.co.za/catalog/product/view/id/224447/s/sans-50458-2008-ed-2-00/ |
SABS 083 | Is the Code of Practice for the Measurement and Assessment of Occupational Noise for Hearing Conservation Purposes, published by the South African Bureau of Standards. https://store.sabs.co.za/catalog/product/view/id/217774/s/sans-10083-2013-ed-5-02/ |
SABS 1451-1:2008 | Standard Specification for Hearing Protectors Part 1 – Ear-Muffs https://store.sabs.co.za/catalogsearch/result/?q=1451 |
SABS 1451-2:2008 | Standard Specification for Hearing Protectors Part 1 – Ear-Plugs. https://store.sabs.co.za/catalogsearch/result/?q=1451 |
SABS 1451-3:2008 | Standard Specification for Hearing Protectors Part 1 – Ear-Muffs attached to an industrial safety helmet. https://store.sabs.co.za/catalogsearch/result/?q=1451 |