Fibrin tissue adhesive was injected into the right ears of four 7-week-old CBA/J mice. Auditory brain stem responses (ABRs) were used to monitor changes in auditory sensitivity over the next 26 days, after which the middle ears and cochleas were examined histologically. Mean maximum ABR threshold shifts were as great as 36 dB, and were larger for higher frequencies than for lower. Maximum shifts occurred between 1 and 8 days; by 26 days, thresholds had returned to intensity levels observed before injection.