Discriminability, Loudness, and Masking in the Rat (Rattus norvegicus): A Confirmation and Extension. (Reannouncement with New Availability Information).

摘要

In Experiment 1, rats discriminated between two sound pressure levels (SPL) of a pure tone: standard (STD) SPLs of 84 and 74 dB and comparison (CO) SPLs 4, 14, and 24 dB below STD were tested in quiet and 60 dB noise at 4 and 12.5 kHz (24 conditions). The decibel difference between STD and CO accounted for only 43.52% of the variance in the signal detection measure of sensitivity, d', across conditions, whereas the loudness difference (LD = STD 0.35 - CO 0.35) accounted for 89.82% of the variance in d'. These results confirm and extend previous observations that: (a) equal decibel differences are not equally discriminable; (b) loudness for the rat increases as a power function of SPL with an exponent of 0.35; and (c) masked loudness is a linear function of loudness in quiet. In Experiment 2, the assumptions of normal distribution and equal variance implicit in the use of the d' measure were examined.