Okanoya, K. and Dooling, R.J. (1987). Strain differences in auditory thresholds in the canary (Serinus canarius). Journal of Comparative Psychology, 101, 213-215.

Canaries (Serinus canarius) of the Belgian waterslager strain from two different colonies were trained with operant techniques for audiometric testing. For both young and old birds, absolute thresholds in the middle- to high-frequency region of the audiogram were between 30 and 40 dB (SPL) higher than those of other song birds, including canaries of other strains. Thus the Belgian waterslager canary, selectively bred for loud, low-pitched song, has also developed poor highfrequency hearing.