A number of years ago, behavioral studies of hearing in this canary showed these birds have very poor hearing at high frequencies compared to other strains of canaries (figure at right). 

Physiological and anatomical studies of the ear and auditory nerve in this species over the last decade have now shown that the high-frequency hearing loss in canaries of this strain is inherited and involves missing and damaged hair cells on the basilar papilla (the sensory surface of the bird hearing organ). This is remarkable because we know that birds, unlike mammals, have the ability to regenerate new auditory hair cells. 

Current studies in the Belgian Waterslager canary show evidence of a low level of continuous supporting cell proliferation and hair cell differentiation that can be increased by killing existing hair cells with ototoxic drugs or high levels of noise. So far, neither this low level of proliferation, nor even the increased level of proliferation from noise exposure or ototoxic drug administration, results in complete repair of the basilar papilla and efforts are underway to understand some of the possible limiting factors.