The effect of early hearing loss on Bobwhites' responses to pure tones: A possible animal model of prelingual deafness

This study aimed to look at the behavioral responses of Bobwhite quail to pure tone stimuli by measuring peep suppression. We also considered if a duration of early hearing loss would affect Bobwhite's responsiveness to the tones. Bobwhites were tested individually at all different ages post hatch day. The pure tones were presented at several different intensity levels and peep suppression was calculated as a measure of responsiveness to the stimuli. Mock trials were conducted as a measure of control to determine the birds' typical peep rate. Some of the Bobwhite quail were injected with gentamicin 0-1 post-hatch day in order to simulate an early hearing loss. The control quail (those who did not experience a period of deafness) were found to be more responsive than the treated Bobwhites (those who experienced a period of deafness). The treated quail were less responsive than the control quail during their period of hearing loss but responsiveness did seem to improve once the hair cells were regenerated. However, the treated quail did not respond nearly as well as the control birds. A period of deafness does seem to have an effect on responsiveness to pure tone stimuli. There also seems to be something occurring, developmentally, at 15-21 days post-hatch. A follow up study would examine the responsiveness to species specific calls. And once accurate thresholds are attained with species specific calls, the effect of a duration of hearing loss on responsiveness on species specific calls can be measured. There is also hope that the quality of hearing following hair cell regeneration may be measured by altering the envelope and fine structure of the species specific call.