Masking for air conduction (AC) is less common than for bone conduction (BC) because?

Masking for air conduction (AC) is less common than for bone conduction (BC) primarily because air conduction tests are associated with a higher inter-aural attenuation. Inter-aural attenuation refers to the reduction of sound intensity as it travels from one ear to the other. In air conduction testing, the amount of sound that crosses over to the non-test ear is greater, which can potentially lead to inaccurate results if masking is not used. However, the inter-aural attenuation for bone conduction is significantly lower, meaning that there is a greater chance that sound presented to one ear could be heard by the other ear.

This increased inter-aural attenuation in air conduction makes it less likely for the non-test ear to interfere with test results, reducing the necessity for masking compared to bone conduction testing. Consequently, the technique hinges on the understanding that while air conduction can allow for potential cross-hearing, the likelihood is lower, thus it requires masking less frequently than bone conduction testing, where such issues arise more often due to its lower inter-aural attenuation. This relationship underscores why masking for air conduction is generally less required in the assessment process.