The auditory thresholds of the cat have been obtained by the conditioned response method. Tests were made for frequencies from 62.5 to 60 000 cps. The upper limit of the cat's hearing is in the neighborhood of 60 000 cps. A comparison of threshold curves for cat and man suggests that the cat may be slightly less sensitive than man for frequencies of 500 cps and below. Sensitivity for the range 500 to 4000 cps is almost the same. For higher frequencies the hearing of the cat is distinctly superior to that of man.