Methodological implications of interaural correlation: count heads not ears.

In a sample of 425 subjects, pure-tone hearing thresholds between the right and left ears were shown to have an average correlation of .885 (or .783 with age partialed out). This high interaural correlation is shown to invalidate the experimental procedure of entering data on the basis of "ears," where each subject can contribute one or two audiograms to the data pool, since such aggregation is demonstrated to produce spuriously high levels of apparent statistical significance in inferential statistical tests.