When is masking needed for bone conduction testing?

Masking is needed for bone conduction testing when there is a sufficient interaural attenuation—the difference in sound level received by each ear—that could result in the sound presented to one ear being heard by the other ear instead. This is particularly important when evaluating patients for conductive or sensorineural hearing loss, as it helps to ensure accurate results.

The correct answer reflects that a 15 dB difference in thresholds between the ears is generally the threshold where masking is considered necessary. If the difference exceeds this level, it indicates that the ear with the better hearing might be responding instead of the poorer ear, potentially leading to inaccurate assessment of the hearing loss in the affected ear. By implementing masking when a 15 dB difference is present, the audiologist can confirm that the test results reflect true conductive or sensorineural hearing thresholds rather than cross-hearing.

The other thresholds mentioned—10 dB, 20 dB, and 40 dB—do not accurately represent the established guidelines for when masking should be introduced in bone conduction testing. A 10 dB difference is generally considered too low to warrant masking since it is within the range of normal fluctuation in hearing capabilities. A 20 dB difference may lead to under-masking in certain