1. The changes in audiological finding after acoustic neuroma (AN) surgery and neurovascular decompression surgery were followed in patients who showed profound deafness postperatively.
2. Pure tone audiometric findings improved markedly within 1 month after surgery and continued to improve gradually thereafter.
3. Speech discrimination improved in parallel with the improvement in pure tone audiometric findings.
4. The stapedius reflex threshold became elevated or was absent after AN surgery but showed no abnormalities after Janetta surgery.
5. In ABR, the latency of wave V became prolonged postoperatively and only a slight improvement thereafter.
6. From these findings, we inferred that the postoperative disorders in pure tone hearing and speech discrimination were due to the disturbance of inner ear circulation caused by surgical manipulation. In addition, the gradual improvement in hearing after the first postoperative month was considered to be due to the improvement in the retrocochlear disorder.