EVALUATING HEARING THRESHOLD DIFFERENCES BETWEEN EARS AS A SCREEN FORACOUSTIC NEUROMA

Differences in pure tone thresholds between ears were evaluated at two different patient care facilities to determine this measure's value a s a screen for acoustic neuroma. We evaluated the audiograms of tumor and nontumor groups to estimate the true positive rates and false posi tive rates for several decision rules. Threshold differences were foun d to be a more effective diagnostic tool for females than for males. H owever, even for the most effective rules, the efficiency of this test alone is mediocre, which indicates that hearing threshold differences between ears must be combined with other criteria for a cost-effectiv e approach to acoustic neuroma identification. Furthermore, tumor size was not predicted by the amount of threshold asymmetry between ears, which suggests that some large, potentially life-threatening tumors ma y be missed if pure tone threshold differences are the sole criterion for referral for additional tests.