What is the internal attenuation for pure tone air conduction testing?

The internal attenuation for pure tone air conduction testing is recognized as 40 dB HL. This value is significant in audiometric testing as it reflects how much sound energy is lost during transmission through the auditory system. When a sound wave travels through the air into the ear canal and reaches the cochlea, some of its intensity diminishes due to various factors, including the physical properties of the ear and the medium through which it travels.

When testing hearing thresholds, especially in situations of masking where a second sound is presented to one ear to prevent it from being perceived by the opposite ear, understanding internal attenuation is critical. The standard internal attenuation value of 40 dB HL indicates that if a sound is presented in one ear at 40 dB above the threshold, it should not be heard in the opposite ear because the sound energy would drop below its auditory threshold due to this attenuation.

This figure is important for determining the effectiveness of masking during audiological assessments, as it helps audiologists decide when it is necessary to mask one ear while testing the other to ensure accurate threshold readings. The other values presented in the choices are not standard and do not correspond to the typical internal attenuation used in pure tone air conduction testing, which is why they are not applicable.