AUDITORY SENSITIVITY OF THE WHITE RAT 



327 



CONCLUSIONS 



(1) There is a practical insensitivity to many pitches in 

 the lower region of the scale for the white rat. This apparently 

 goes along with a sensitivity to noises of the same predominant 

 pitch. 



(2) Differences in tonal complexity and intensity may be 

 considerable without making discrimination possible. 



(3) Apparent reactions to tone are most probably made to 

 accompanying noises. 



(4) If, after all, there is a sensitivity to tonal stimuli as 

 here tested, then, for the rat, tones and noises are very different 

 classes of stimuli. 



APPENDIX 



Chronological statement of controls used with rats in whistle 

 tests. 



