Publication:

Extended high frequency hearing sensitivity in normal contralateral ears exposed to mastoid drill noise in patients undergoing mastoid surgery

Background This study aimed at evaluation of extended high frequency hearing in non operated normal ear in patients undergoing mastoid surgery using otological micro drill.

Methods A hospital based prospective observational study was carried out. Patients up to 40 years of age with unilateral ear disease were recruited and divided into two groups- mastoidectomy group comprising 30 patients who underwent mastoid surgery using high speed microdrill and tympanoplasty group who underwent surgery without using microdrill. Pure tone audiometry (conventional and extended high frequency) was performed preoperatively, on 3rd and 10th postoperative day.

Results In mastoidectomy group, Air conduction thresholds in extended high frequency showed significant changes on 3rd postoperative day and showed recovery by 10th postoperative day. Recovery started by 3rd postoperative day and in majority of cases there was a complete recovery by 10th postoperative day.

Conclusions Otological drilling has a significant effect on the extended high frequency hearing of normal contralateral ear. Extended high frequency audiometry till 16000 Hz is a sensitive modality for evaluation to monitor these cases on post-operative follow up.