Auditory sensitivity of the albino rat

Auditory sensitivity of the albino rat was determined using the conditioned suppression of licking technique. The rat was found to have a range of sensitivity to pure tones from 250 Hz to 80 kHz at 70 dB SPL. The point of maximum sensitivity was 8 kHz closely rivaled by higher frequencies up to 38 kHz. Withing this band, tones were detectable at sound pressures from 2–7 dB SPL. For frequencies above 38‐kHz sensitivity rapidly decreased at a rate of about 50 dB per octave. For frequencies below 8‐kHz sensitivity decreased at a rate of about 20 dB per octave. The audiogram supports previous evidence of good hearing around 32–38 kHz [G. Gourevitch and M. H. Hack, J. Comp. Physiol. Psych. 62, 289–291 (1966)], but does not support the idea that the albino rat's hearing is narrowly tuned to this range. Thus, the sensitivity of the albino rat to these frequencies reflects the broadly tuned high frequency hearing which is generally quite good in small mammals, rather than representing a specialized feature of its...