Differential Sensitivity for Alternate Interaural Loudness Balancing in the Psychoacoustic Calibration of Earphones.

摘要

The variances were examined associated with the psychoacoustic calibration of audiometric earphones by the usual method of alternate interaural loudness balancing with a standard earphone first on one side of the head and then on the other. Eight major sources of variance can be identified, the result of coupling two earphones first on one ear and then on the other, collecting two absolute thresholds first on one ear and then on the other using the standard earphone, and collecting two interaural loudness balances. On 13 subjects the differential sensitivity for alternate interaural loudness balancing was 1.5 - 2.5 dB, the higher frequencies giving somewhat larger values. Variances due to coupling and to absolute threshold testing were estimated at about 1 dB for the former and from 1.27 - 2.51 dB for the latter. It was considered that the sizes of these variances were quite sufficient to explain the test-retest consistency of mean transfer functions, which were of the order of 6 dB. The group mean transfer function could be specified for either of two new circumaural earphones with a precision of 0.92 - 4.84 dB at various audiometric frequencies (plus or minus 1 Standard Error). (Author)