Occupational audiometry is the systematic measurement of hearing thresholds for employees exposed to workplace noise. Its purpose is to establish a reliable reference audiogram and compare later results with that reference so that a significant change can be identified and acted upon. Audiometry is part of a hearing conservation programme, not a substitute for controlling noise. It does not show the employee's daily exposure and cannot identify every possible cause of hearing change. Exposure monitoring determines the workplace noise conditions, while audiometry measures the employee's response to pure tones under controlled test conditions. Within the Emirate of Abu Dhabi, the applicable requirements are contained in ADOSH-SF Code of Practice CoP 3.0 Occupational Noise, Version 4.0, dated 15 July 2024. The Code is administered by the Abu Dhabi Public Health Centre and applies to employers within Abu Dhabi.
Under ADOSH-SF CoP 3.0, applying within the Emirate of Abu Dhabi, audiometric testing must be made available at no cost to each employee exposed at or above an eight-hour time-weighted average of 85 dB(A). Eligibility is based on occupational-noise exposure calculated without allowing for attenuation from hearing protection.
Testing must be performed by a licensed or certified audiologist, otolaryngologist or other physician, or by a technician certified or accredited by the Department of Health who reports to one of those professionals. This arrangement ensures that testing is performed competently and that significant findings are reviewed by a person qualified to determine the appropriate follow-up.
The technician's role includes preparing the employee, checking the equipment, conducting the test consistently and recording the results accurately. Professional supervision includes review of the audiogram, comparison with the baseline and consideration of whether further clinical audiological or otological evaluation is appropriate.
The employer should maintain a reliable system for identifying employees who require testing and for arranging appointments without avoidable delay. Employees who move between roles or begin work in noisy areas should not be overlooked because their original job was not included in the programme.
The baseline audiogram establishes the reference against which later audiograms are compared. It should represent the employee's hearing thresholds before further workplace exposure has had an opportunity to influence the result.
Under ADOSH-SF CoP 3.0, applying within Abu Dhabi, the baseline audiogram is obtained within 6 months of the employee's first exposure at or above an eight-hour time-weighted average of 85 dB(A). The baseline is preceded by at least 14 hours without workplace noise exposure. Hearing protectors may be used as a substitute for that quiet period.
The employee should be informed of the need to avoid workplace noise before the test and of any arrangements for using hearing protection during the relevant period. The quiet-period requirement is intended to reduce the possibility that a temporary threshold shift caused by recent exposure is incorporated into the baseline.
A baseline should not be treated as a routine administrative measurement. If the result appears unreliable, inconsistent or affected by test conditions, the supervising professional should determine whether further assessment or repeat testing is needed before it is accepted as the reference.
Information accompanying the baseline should identify the employee, test date, examiner, equipment, test location and relevant occupational-noise history. This supports later comparison and helps distinguish a genuine threshold change from a difference caused by equipment, test technique or environmental conditions.
Under ADOSH-SF CoP 3.0, applying within the Emirate of Abu Dhabi, the annual audiogram is obtained within 12 months of the baseline and is conducted under the same requirement for at least 14 hours without workplace noise exposure, with hearing protectors permitted as a substitute for the quiet period.
The annual audiogram is compared with the employee's baseline to determine whether a standard threshold shift has occurred. Comparison should consider each ear separately because a significant change may affect only one ear.
Consistent testing conditions improve the value of longitudinal comparison. Changes in equipment, examiner, room or employee preparation do not necessarily invalidate a result, but they should be controlled and documented so that apparent changes are not created by inconsistent procedure.
Audiometry should not be viewed as a pass-or-fail examination. An audiogram records the lowest sound levels detected by the employee at the tested frequencies under the test conditions. The pattern and change over time require professional interpretation.
Where an audiogram is incomplete or unreliable, the issue should be resolved rather than carrying the result forward unquestioned. Earphone placement, misunderstanding of the test instructions, background noise, recent exposure or equipment performance can affect the measurement.
Under ADOSH-SF CoP 3.0, applying within Abu Dhabi, testing is by pure-tone air conduction, with each ear tested separately at 500, 1000, 2000, 3000, 4000 and 6000 Hz as a minimum.
Pure-tone testing presents tones at selected frequencies and adjusts their level to determine the employee's hearing threshold. Testing each ear separately allows asymmetry and frequency-specific changes to be identified.
The required frequencies include lower-frequency regions relevant to general hearing sensitivity and higher-frequency regions where occupational-noise-related change may first become apparent. The clinical meaning of the pattern, including the relationship between higher-frequency change and everyday speech, is addressed separately on the noise-induced-hearing-loss page.
Clear instructions are important because the test depends on the employee responding whenever a tone is heard, even when it is faint. The examiner should confirm that the employee understands the response method before threshold measurement begins.
The employee should also have an opportunity to report matters that may affect the test, such as current ear discomfort, recent unusually loud exposure or difficulty understanding the procedure. Such information does not determine the outcome but may assist the supervising professional in interpreting the result.
Reliable audiometry depends on equipment that is functioning correctly and remains within calibration. Under ADOSH-SF CoP 3.0, applying within the Emirate of Abu Dhabi, audiometers must conform to ANSI S3.6-2010 or ISO 8253-1:2010.
A functional check is carried out before each day's use. Under the same Abu Dhabi Code, a deviation of 10 dB or more requires acoustic calibration. The daily check is intended to identify obvious faults or changes before employees are tested.
An annual calibration check is also required. Under ADOSH-SF CoP 3.0, applying within Abu Dhabi, a deviation of 15 dB or more requires exhaustive calibration. Exhaustive calibration is required at least every two years.
Calibration documentation should identify the equipment, date, results, person or laboratory completing the work and any corrective action. Equipment that fails a required check should not remain in routine use until its condition has been resolved.
Earphones and other components should remain associated with the audiometer configuration for which calibration has been established unless the replacement arrangement is appropriately checked. Physical condition should also be inspected because damaged cushions, cables or connectors can affect performance or test consistency.
Audiometry requires a sufficiently quiet environment. Background sound can mask the test tone, particularly at lower frequencies, and can make an employee appear to have a poorer threshold than is actually the case.
Under ADOSH-SF CoP 3.0, applying within the Emirate of Abu Dhabi, the maximum test-room background sound pressure levels are 40 dB at 500 Hz, 40 dB at 1000 Hz, 47 dB at 2000 Hz, 57 dB at 4000 Hz and 62 dB at 8000 Hz.
The background levels are measured with equipment meeting at least ANSI S1.4-1983 (R2006) Type 2 and ANSI S1.11-2004 (R2009) Class II. The room assessment should reflect the conditions under which tests are actually conducted.
A room may appear quiet while still containing ventilation noise, low-frequency plant noise, conversations, door movement or intermittent external sound that interferes with testing. Conditions should therefore be verified by measurement rather than judged only by listening.
The test should be paused or rescheduled where an unexpected noise event compromises the result. A technically compliant room does not prevent disturbance if doors are opened, people enter or nearby equipment operates during the test.
Under ADOSH-SF CoP 3.0, applying within Abu Dhabi, a standard threshold shift is an average change of 10 dB or more at 2000, 3000 and 4000 Hz in either ear compared with the baseline. No allowance is made for presbycusis.
When a standard threshold shift is identified, the finding triggers defined follow-up rather than merely being placed on file. Under the same Abu Dhabi Code, the employee is informed in writing within 21 days in a language the employee understands.
The employee is refitted with hearing protectors and required to use them. The attenuation provided by the protectors is re-evaluated and the protection is upgraded where necessary. The programme should also examine exposure results, work practices, controls and any workplace change that may have contributed to increased risk.
Referral for clinical audiological or otological evaluation is made as appropriate. A retest may be obtained within 30 days and treated as the annual audiogram. The decision about interpretation and referral belongs with the qualified professional responsible for the audiometric programme.
A standard threshold shift does not by itself establish the cause of the change. The purpose of follow-up is to protect the employee, check the reliability and significance of the result, and ensure that workplace arrangements remain adequate.
Within the Emirate of Abu Dhabi, occupational audiometry for employees meeting the exposure criterion is governed by mandatory ADOSH-SF CoP 3.0 Occupational Noise under the authority of the Abu Dhabi Public Health Centre. The audiometric duties described on this page are Abu Dhabi requirements, not UAE federal requirements. No equivalent published requirement has been identified for the other emirates or at federal level, although ADOSH-SF CoP 3.0 and recognised international practice are commonly used as references where no local instrument applies.
No. An audiogram records hearing thresholds at the time of testing. Exposure monitoring and workplace assessment are still required to determine whether noise controls are adequate.
It may be suitable only where it satisfies the applicable timing, quiet-period, test-method, calibration and professional-supervision requirements. Its suitability should be confirmed before it is adopted as the occupational baseline.
Separate testing allows differences between ears to be identified and ensures that a significant change affecting either ear is not concealed by combining the results.
Recent exposure can temporarily affect hearing thresholds. The supervising professional should be informed so that the validity of the test and the need for rescheduling or retesting can be considered.
No. It is a defined change from the occupational baseline that triggers notification and follow-up. Clinical interpretation and consideration of possible causes require an appropriately qualified professional.