Identification of serious hearing loss with acoustic reflex data. Clinical experience with some new guidelines

The acoustic stapedial reflex was activated by a broad-band noise signal for 326 adult subjects. Two groups were formed on the basis of pure-tone audiometry findings. Two hundred and four subjects were normal hearers or showed, at most, a mild hearing loss with a pure-tone average (500, 1000, 2000, and 4000 Hz) of less than 35 dB HL. One hundred and twenty-two subjects showed a serious hearing sensitivity impairment with a pure-tone average of 35 dB HL or greater. These acoustic reflex data were then applied prospectively in the identification of hearing impairment. Hearing sensitivity status was accurately differentiated in over three-fourths of the population. Serious hearing loss was invariably found for subjects with acoustic reflex threshold levels equal to or greater than 110 dB SPL, whereas it was effectively ruled-out by acoustic reflex thresholds in the 60 through 80 dB SPL range. The proportion of subjects with clinically significant hearing impairment is described for intermediate acoustic reflex threshold levels. These guidelines are offered as a feasible first step in clinical differentiation of hearing sensitivity status.