Occupational Health and Safety Act, 1993 (Act No. 85 of 1993)RegulationsNoise Exposure Regulations, 2024Code of Practice for Audiometry12. Audiometric Testing |
| 12.1 | Screening Audiometric Testing |
| 12.1.1 | Screening audiometric testing, including baseline, entry, initial, periodic and exit audiometry, must be conducted on— |
| (a) | all employees who are to be employed in or who are employed in a noise zone; or |
| (b) | vulnerable employees. |
| 12.2 | Baseline Audiometry |
| 12.2.1 | A baseline audiometric test must be conducted— |
| (a) | on every employee who meets the requirement of 12.1.1; and |
| (b) | before or within 30-days of employment. |
| 12.2.2 | The baseline audiometric test in terms of 12.2.1 must establish— |
| (a) | a baseline PLH, which will serve as a reference PLH against which all future PLH shifts will be compared; and |
| (b) | the audiometric zero for the purpose of calculating the STS against which all future STS will be compared. |
| 12.2.3 | To be considered valid, the baseline audiometric test must comply with— |
| (a) | reliability criteria; and |
| (b) | validity criteria. |
| 12.2.3.1 | Reliability criteria must consist of the following requirements: |
| (a) | audiometer (clause 6); |
| (b) | calibration of audiometer (clause 7); |
| (c) | acoustic environment (clause 8); |
| (d) | employee factors (clause 9); |
| (e) | methods (clause 10); and |
| (f) | audiogramme report (clause 11). |
| 12.2.3.2 | Validity criteria as referenced in Instruction 171, Supplement 171,— |
| (a) | consists of two audiogrammes done— |
| (i) | on the same day; |
| (ii) | in the same setting; |
| (iii) | in two different sittings; and |
| (iv) | after at least 16-hours free from any noise exposure without the use of HPDs. |
| (b) | the hearing thresholds in the two audiogrammes for each ear at any frequency from 500 to the 4 000 Hz must not differ by more than 10 dB. |
| 12.2.4 | Once a valid baseline audiometric test has been established, the audiogramme with the lowest PLH will be regarded as the baseline for that employee. |
| 12.2.5 | Where a screening audiometric test is unable to establish a valid baseline audiometric test, the screening test must be repeated after another interval of 16-hours free from exposure to noise (without the use of HPD). If the repeat screening test is still unable to establish a valid baseline audiometric test, the employee must be referred to an audiologist to establish a valid baseline audiometric test using appropriate techniques or methodologies as referenced in Instruction 171. This process must be completed, as far as is reasonably practicable, within the 30-day deadline. |
| 12.2.6 | Where a valid baseline audiometric test has not been established or is not available for the period 1 May 2001 to 16 November 2003 or for employees employed in a noise zone after November 2003— |
| (a) | the baseline PLH will be considered to be 0%; and |
| (b) | the audiometric zero will be regarded as zero. |
| 12.3 | Audiometric zero and Standard Threshold Shift |
| 12.3.1 | Audiometric zero and STS are recorded for prevention purposes. |
| 12.3.2 | Audiometric zero is determined from an average calculated at 2 000, 3 000 and 4 000 Hz. |
| 12.3.3 | The audiometric zero must be used in determining any future deterioration in hearing loss. |
| 12.3.4 | Determination of audiometric zero |
| 12.3.4.1 | For employees employed after the promulgation of the Noise Exposure Regulations, the audiometric zero shall be established from a valid baseline. |
| 12.3.4.2 | For employees employed before the promulgation of the Noise Exposure Regulations, the audiometric zero shall be established from their existing baseline. |
| 12.3.4.3 | For any employee for whom a valid baseline is not available, the audiometric zero shall be zero. |
| 12.4 | Entry Audiometry |
| 12.4.1 | An entry audiometric test must be conducted— |
| (a) | on a new employee who— |
| (i) | meets the requirement of 12.1.1; and |
| (ii) | previously met the requirement of 12.1.1 at a previous employer; |
| (b) | on employees who have a valid baseline or do not have a valid baseline; and |
| (c) | before or within 30-days of employment. |
| 12.4.2 | Where reasonably practicable and relevant, a new employee must provide a copy of their baseline audiometric test. |
| 12.4.3 | The entry audiometric test must establish— |
| (a) | PLH shifts from baseline; |
| (b) | STS comparison against audiometric zero; |
| (c) | effectiveness of preventive interventions; |
| (d) | the need for reporting in terms of clause 13; and |
| (e) | the need for referral for diagnostic audiology. |
| 12.4.4 | To be considered valid, the entry audiometric test must comply with— |
| (a) | reliability criteria; and |
| (b) | validity criteria. |
| 12.4.4.1 | Reliability criteria must consist of the following requirements— |
| (a) | audiometer (clause 6); |
| (b) | calibration of audiometer (clause 7); |
| (c) | acoustic environment (clause 8); |
| (d) | employee factors (clause 9); |
| (e) | methods (clause 10); and |
| (f) | audiogramme report (clause 11). |
| 12.4.4.2 | Validity criteria as referenced in Instruction 171, Supplement 171,— |
| (a) | consists of two audiogrammes done— |
| (i) | on the same day; |
| (ii) | in the same setting; |
| (iii) | in two different sittings; and |
| (iv) | after at least 16-hours free from any noise exposure without the use of HPDs; and |
| (b) | the hearing thresholds in the two audiogrammes for each ear at any frequency from 500 to 4 000 Hz must not differ by more than 10 dB. |
| 12.4.5 | Once a valid entry audiometric test has been conducted, the audiogramme with the lowest PLH will be regarded as the entry audiometric test for that employee. |
| 12.5 | Initial Audiometry |
| 12.5.1 | An initial audiometric test must be conducted on every employee exposed to noise in terms of 12.1.1 where there is no valid baseline and/or valid entry audiometric test. |
| 12.5.2 | An initial audiometric test must be conducted— |
| (a) | on an employee who meets the requirement of 12.1.1; and |
| (b) | within 18-months of the publication of the Noise Exposure Regulations and this Code. |
| 12.5.3 | The initial audiometric test must establish— |
| (a) | PLH shifts from baseline; |
| (b) | STS comparison against audiometric zero; |
| (c) | effectiveness of preventive interventions; |
| (d) | the need for reporting in terms of clause 13; and |
| (e) | the need for referral for diagnostic audiology. |
| 12.5.4 | To be considered valid, the initial audiometric test must comply with— |
| (a) | reliability criteria; and |
| (b) | validity criteria. |
| 12.5.4.1 | Reliability criteria must consist of the following requirements— |
| (a) | audiometer (clause 6); |
| (b) | calibration of audiometer (clause 7); |
| (c) | acoustic environment (clause 8); |
| (d) | employee factors (clause 9); |
| (e) | methods (clause 10); and |
| (f) | audiogramme report (clause 11). |
| 12.5.4.2 | Validity criteria as referenced in Instruction 171, Supplement 171— |
| (a) | consist of one audiogramme; and |
| (b) | must be conducted after at least 16-hours free from any noise exposure without the use of HPDs. |
| 12.6 | Periodic Audiometry |
| 12.6.1 | A periodic audiometric test must be conducted on every employee who meets the requirement of 12.1.1; |
| 12.6.2 | The periodic audiometric test must be conducted— |
| (a) | every 12-months for exposures— |
| (i) | at or above 85 dBA but less than 105 dBA; or |
| (ii) | at or above 82 dBA with concomitant exposure to ototoxic chemical agents and/or whole body vibration but less than 105 dBA; |
| (b) | every 6-months for exposures at or above 105 dBA; |
| (c) | every 6-months for exposures at or above 135 dBC; or |
| (d) | at more frequent intervals if recommended by the occupational health practitioner (OHP) based on clinical evidence. |
| 12.6.3 | For an employee whose STS has not exceeded 25 dB over a period of 3-years, an OMP may extended the frequency of periodic audiometric test to— |
| (a) | 24-months for employees exposed in terms of 12.6.2 (a); and |
| (b) | 12-months for employees exposed in terms of 12.6.2 (b). |
| 12.6.4 | The periodic audiometric test must establish— |
| (a) | PLH shifts from baseline; |
| (b) | STS comparison against audiometric zero; |
| (c) | effectiveness of preventive interventions; |
| (d) | the need for reporting in terms of clause 13; and |
| (e) | the need for referral for diagnostic audiology. |
| 12.6.5 | To be considered valid, the periodic audiometric test must comply with— |
| (a) | reliability criteria; and |
| (b) | validity criteria. |
| 12.6.5.1 | Reliability criteria must consist of the following requirements— |
| (a) | audiometer (clause 6); |
| (b) | calibration of audiometer (clause 7); |
| (c) | acoustic environment (clause 8); |
| (d) | employee factors (clause 9); |
| (e) | methods (clause 10); and |
| (f) | audiogramme report (clause 11). |
| 12.6.5.2 | Validity criteria as referenced in Instruction 171, Supplement 171— |
| (a) | consists of one audiogramme; and |
| (b) | where reasonably practicable, must be conducted after a period of at least 16-hours free from any noise exposure without the use of HPDs: Provided that the correct wearing of HPDs while performing work in a noise zone prior to the periodic audiometric test must be deemed as meeting the 16-hour period free from noise exposure. |
| 12.7 | Diagnostic Audiology |
| 12.7.1 | A diagnostic audiometric test must be conducted on all employees exposed to noise in terms of 12.1.1, where— |
| (a) | screening audiometry identifies a PLH shift greater than 10% from baseline; |
| (b) | the hearing loss pattern suggests NIHL; and |
| (c) | screening audiometry identifies an STS shift of 25 dB or more from audiometric zero. |
| 12.7.2 | To be considered valid, the diagnostic audiometric test must comply with— |
| (a) | reliability criteria; and |
| (b) | validity criteria. |
| 12.7.2.1 | Reliability criteria must consist of the following requirements— |
| (a) | audiometer (clause 6); |
| (b) | calibration of audiometer (clause 7); |
| (c) | acoustic environment (clause 8); |
| (d) | employee factors (clause 9); |
| (e) | methods (clause 10); and |
| (f) | audiogramme report (clause 11). |
| 12.7.2.2 | Validity criteria as referenced in Instruction 171, Supplement 171, includes— |
| (a) | a test conducted by an audiologist or ENT specialist; |
| (b) | two sets of the battery of diagnostic audiometric tests; |
| (c) | a period of at least 24-hours free from any noise exposure without the use of HPDs; |
| (d) | a test conducted on the same day; and |
| (e) | two diagnostic audiometric tests that do not differ by more than 10 dB at any frequency used to determine the PLH. |
| 12.7.3 | Where, after 3 attempts by the audiologist, it is not possible to obtain a diagnostic audiogramme that meets the validity criteria, the employee must be referred to an ENT specialist, as soon as reasonably practicable, to determine the hearing loss. |
| 12.7.4 | Where, after 3 attempts by the ENT specialist, it is not possible to obtain a diagnostic audiogramme that meets the validity criteria, the test must be deferred for a period of 6-months. |
| 12.7.5 | The diagnostic audiometric test used to compensate an employee for NIHL must be deemed as that employee's new baseline. |
| 12.8 | Exit Audiometry |
| 12.8.1 | An exit audiometric test must be conducted on every employee who was exposed to noise in terms of 12.1.1. |
| 12.8.2 | The exit audiometric test must be conducted within 30-days prior to or 30-days after date of termination of employment in a noise zone. |
| 12.8.3 | A valid audiometric test conducted within 6-months prior to date of termination of employment shall be deemed to have fulfilled the requirements of an exit audiometric test. |
| 12.8.4 | The exit audiometric test must establish— |
| (a) | PLH shifts from baseline; |
| (b) | STS comparison against audiometric zero; |
| (c) | effectiveness of preventive interventions; |
| (d) | the need for reporting in terms of clause 13; and |
| (e) | the need for referral for diagnostic audiology. |
| 12.8.5 | To be considered valid, the exit audiometric test must comply with— |
| (a) | reliability criteria; and |
| (b) | validity criteria. |
| 12.8.5.1 | Reliability criteria must consist of the following requirements— |
| (a) | audiometer (clause 6); |
| (b) | calibration of audiometer (clause 7); |
| (c) | acoustic environment (clause 8); |
| (d) | employee factors (clause 9); |
| (e) | methods (clause 10); and |
| (f) | audiogramme report (clause 11). |
| 12.8.5.2 | Validity criteria as referenced in Instruction 171, Supplement 171, includes— |
| (a) | one audiogramme; and |
| (b) | where reasonably practicable, a period of at least 16-hours free from any noise exposure without the use of HPDs: Provided that the correct wearing of HPDs while performing work in a noise zone prior to the periodic audiometric test must be deemed as meeting the 16-hour period free from noise exposure |