What is the minimum difference in dB for delivering NBN when masking for BC?

In the context of auditory assessments, specifically when discussing bone conduction (BC) and the need for masking, it is essential to understand the concept of "NBN," which refers to narrowband noise. When conducting a hearing evaluation, particularly involving both air conduction (AC) and bone conduction testing, masking is used to prevent the non-test ear from contributing to the test results, ensuring that the findings accurately reflect the hearing capabilities of the test ear alone.

The minimum difference of 15 dB is significant when determining the necessity for masking. This threshold is established to ensure that the masked sound reaches only the intended ear without interference from the non-test ear. A 15 dB difference allows sufficient intensity to present the masking noise effectively and accurately while minimizing the risk of cross-hearing.

Thus, specifying a 15 dB minimum difference ensures that the test results are reliable and valid. It is a widely accepted standard in audiological practices, providing a balance between effective masking and minimizing extraneous variables that could affect the outcome of the audiometric evaluation.