What happens when the presentation level of the tone exceeds the interaural attenuation?

When the presentation level of the tone exceeds the interaural attenuation, masking is required. Interaural attenuation refers to the reduction of sound energy that occurs when sound travels from one ear to the other, typically measured in decibels. If the intensity of the tone presented to the test ear is higher than this attenuation threshold, it can cause the non-test ear to also perceive the sound. This can lead to inaccurate threshold measurements since the response could originate from the non-test ear rather than the intended test ear.

In clinical practice, masking is utilized to ensure that the non-test ear remains inactive and does not influence the results of the hearing test. By introducing a masking noise into the non-test ear, the audiologist can control for cross hearing, allowing for a more accurate assessment of the hearing thresholds for the test ear. Thus, when the presentation level exceeds the interaural attenuation, masking becomes essential to isolate the ear being tested and obtain valid results.