What is the required difference for effective masking when using headphones for air conduction?

The required difference for effective masking when using headphones for air conduction is 40 dB. This threshold is based on the need to ensure that any background noise or external sounds do not interfere with the test results for the ear being evaluated.

When conducting audiometric testing, especially in cases where there may be a significant difference in hearing levels between the ears, effective masking is essential to prevent cross-hearing. A masking level that is 40 dB greater than the threshold of the non-test ear is necessary to ensure that the pure tone signals presented to the test ear are perceived accurately without being influenced by sounds that may be heard in the non-test ear. This 40 dB difference provides a reliable guideline for audiologists and hearing professionals to achieve the most accurate results in hearing assessments.