Predicting hearing level from the acoustic reflex. A comparison of three methods.

Three prediction methods based on the acoustic reflex noise-tone difference (NTD) were used to predict hearing level in 370 subjects. The methods were two versions of the sensitivity prediction by acoustic reflex (SPAR) and a formula for estimating hearing threshold level. With each method, hearing loss was correctly predicted in more than one half of the subjects, while serious predictive error occurred in less than 10%. Age was found to be an important factor in hearing level prediction. Predictive accuracy for each method decreased systematically as a function of age. Predictive accuracy for the two SPAR methods decreased dramatically in subjects with minor middle ear and/or tympanogram abnormalities. Nevertheless, the value of the acoustic reflex NTD in predicting hearing level was confirmed.