PURE TONE AUDIOMETRY
Pure tone audiometry (PTA) is the key hearing test used to identify hearing threshold levels of an individual, enabling determination of the degree, type and configuration of a hearing loss. The measurements involving the peripheral and central auditory systems thus provide the basis for diagnosis and management. PTA is a subjective, behavioural measurement of hearing threshold, as it relies on the patient’s response to pure tone stimuli. It typically, the test takes place in a controlled environment using audiometry equipment. It has segments to measure sensitivity to pitch via calibrated sound frequencies, usually ranging from 125 to 8000 Hz, and measurements of bone conduction and air conduction. The results of PTA are reflected on an audiogram, in which the normal hearing threshold is represented as a horizontal straight line at 0. Studying the curve on the audiogram often indicates the kind of hearing loss; however the results should be supplemented with objective tests.