When should NBN masking be delivered to the NTE?

NBN masking, or Narrow Band Noise masking, should be delivered to the Non-Test Ear (NTE) when there is a 70 dB or greater difference between the thresholds of the test ear and the non-test ear. This approach is based on the principle of effective masking to ensure that the threshold measured in the test ear truly reflects that ear’s sensitivity without the influence of sound being perceived from the non-test ear.

When the difference reaches this level, it indicates that the stimulus may cross over to the non-test ear if masking is not applied, leading to inaccurate results during hearing assessments. By implementing NBN masking under these conditions, auditors can effectively limit cross-hearing, allowing for a clearer evaluation of the hearing thresholds in the test ear. Therefore, applying NBN masking at a 70 dB difference is essential for obtaining valid audiometric results.