Recently, behavioural thresholds obtained in canaries of the Belgian Waterslager strain showed that these birds have an
inherited auditory deficit. Canaries of this strain have absolute auditory thresholds at frequencies above 2.0 kHz that are as much
as 40 dB above the threshold of canaries of other strains. We obtained audiograms from cochlear microphonics and from
compound action potentials from the 8th nerve of Waterslager and non-Waterslager canaries and compare these results to
previous behavioural data on hearing in this species. We also examined the growth of evoked potential amplitude-intensity functions in Waterslager and non-Waterslager canaries. Together with reflectance measurements of middle-ear function from both Waterslager and non-Waterslager canaries, we conclude that the origin of the auditory deficit in Waterslager canaries lies in the cochlea.