Design and methods: A cross-sectional study was conducted on 220 ears diagnosed as having CSOM with an equal number of tinnitus and without tinnitus groups. Only those with normal cochlear function based on conventional pure tone audiometry (250 Hz to 8 kHz) were included. They were further tested for hearing at extended high frequencies of up to 16 kHz. The severity of tinnitus was tested using a tinnitus questionnaire.
Results: The prevalence of extended high frequency hearing loss in the normal cochlear function CSOM patients with tinnitus was 81.8% (95% CI 74.5%, 89.1%), whereas the prevalence in the tinnitus negative group was 30.0% (95% CI 21.3%, 38.7%). There was a significant association between extended high frequency hearing loss and tinnitus in CSOM patients (P