In masking, what does the term 'crossover' refer to?

In the context of masking during audiometric testing, 'crossover' specifically refers to the phenomenon where sound presented to one ear is heard by the opposite, or non-test ear. This occurs due to the transmission of sound through the skull, which can lead to misleading test results if not properly accounted for.

When testing a patient's hearing threshold in one ear, if sound leakage reaches the non-test ear, it can stimulate that ear and mask the true threshold of the test ear. Therefore, effective masking techniques are employed to ensure that the non-test ear does not contribute to the audiometric results, allowing for an accurate assessment of hearing ability.

Other terms relevant to audiological assessment, such as interaural attenuation, refer to the differences in sound intensity level at which a stimulus will cross over to the non-test ear, but crossover itself directly pertains to the presence of sound in the non-test ear during testing.