Pure tone audiometry (PTA) is the key hearing test used to identify hearing threshold levels of an individual. This enables the audiologist to determine of the degree, type and configuration of an individual’s hearing loss, and thus the basis for diagnosis and management. PTA is a subjective, behavioural measurement of hearing threshold, as it relies on patient response to pure tone stimuli. Therefore, PTA is used on adults and children old enough to cooperate with the test procedure. As with most clinical tests, calibration of the test environment, the equipment and the stimuli to ISO standards is needed before testing proceeds.