When should masking be applied during bone conduction threshold testing?

Masking during bone conduction threshold testing is primarily applied to eliminate the influence of cross-hearing, particularly in the context of identifying true hearing thresholds. When there is an air-bone gap of at least 15 dB, it indicates that there is a significant difference in the thresholds between air conduction and bone conduction. This means that sound delivered via air conduction has the potential to be perceived by the better hearing ear, leading to inaccurate results. By applying masking in this scenario, the examiner can ensure that the sound is effectively presented to the intended ear, thereby obtaining a more accurate representation of the hearing ability of that ear.

This approach is vital for qualifying the results to ensure they are reflective of the individual's true auditory capabilities rather than influenced by lateralization effects that can arise from significant air-bone gaps. Ensuring that masking is applied in such circumstances prevents misinterpretation of hearing results, allowing for better diagnostic and rehabilitative decisions.

The other conditions mentioned, such as air-bone gaps of 10 dB, equal thresholds for both ears, or conducting the test in a soundproof room, do not sufficiently guarantee the need for masking because they either do not eliminate the possibility of cross-hearing or they do not exploit the threshold differences necessary for