Predictors for noise sensitivity: how to use them for a prognostic test

In an exploratory study with the aim of devising a test for noise sensitivity, we had examined the prognostic value of numerous parameters for the development of noise-induced hearing loss. The predictors which showed the highest determination within the framework of a standardized noise exposure were: systolic blood pressure general health finger pulse amplitude recovery temporary threshold shift (TTS) at 12 kHz. The total sample population produced varying patterns of reaction. As we assume that sensitivity occurs when a person with normal hearing reacts in a similar manner to a person with noise-induced hearing loss, we began by extrapolating a standard reaction type for each subsample. We then looked for those parameters where the difference between values with and without exposure was greatest. This step is of considerable significance with regard to the practicability of screening tests. The most sensitive parameters to emerge were: diastolic blood pressure on and off finger pulse reaction TTS between 3 and 6 kHz. We were then able to compare individual reactions with the standard reaction types, taking into account intervention by possible variables. Our results were not uniform, but they permit the conclusion that certain reaction types are genetically determined. This, in turn, suggests that the same might apply to the development of noise-induced hearing loss.