What is the formula used to determine the need for masking in air conduction testing?

The need for masking in air conduction testing is determined by comparing the air conduction threshold of the test ear (ACte) with the interaural attenuation (IA). The formula involves subtracting the interaural attenuation from the air conduction threshold of the test ear.

When the air conduction threshold of the test ear minus the interaural attenuation is greater than the bone conduction threshold of the non-test ear, this indicates that the test ear may be responding at least partly to sounds that are heard in the non-test ear. In such cases, masking is necessary to ensure that the non-test ear does not contribute to the response of the test ear.

By understanding this principle, audiologists and hearing aid dispensers can effectively determine when masking is required to obtain accurate hearing assessment results. It ensures that the evaluations reflect true auditory function in the test ear without interference from the non-test ear.