Frequency-Specific Hearing Results After Surgery for Chronic Ear Diseases

OBJECTIVES: To analyze frequency-specific hearing results after surgery for chronic ear diseases while considering pathological findings and various surgical factors. METHODS: Patients who underwent surgical management of chronic otitis media were reviewed retrospectively (n=559). Using pure tone audiometry, air conduction (AC), bone conduction (BC), and air bone gap (ABG) change between pre- and post-operative tests were calculated for the frequencies of 250, 500, 1,000, 2,000, 3,000, 4,000 (AC and BC), and 6,000 Hz (AC). Frequency-specific results were investigated, considering various surgical factors, such as type of surgery, type of ossiculoplasty and pathological findings. RESULTS: AC results in the intact canal wall mastoidectomy showed improvement at each frequency except 4,000, 6,000 Hz. AC results in the tympanoplasty showed improvement at each frequency except 6,000 Hz. AC and ABG results in the open cavity mastoidectomy showed improvement only at the frequencies of 250, 500, 2,000 Hz. AC and ABG improved at low and mid frequencies but not in high frequencies above 3,000 Hz when ossicular reconstruction was conducted. AC and ABG results also improved at low and mid frequencies in the cholesteatoma, and ABG results improved at all frequencies except 3,000 Hz in the non-cholesteatoma. CONCLUSION: After chronic ear surgery, AC and ABG changes improved, primarily in the low and mid frequencies. Further evaluation and studies for post-operative hearing loss at high frequencies are recommended for rehabilitation of hearing ability after surgery.