Which of the following causes maximum hearing loss?
Complete obstruction of ear canal
Perforation of tympanic membrane
Ossicular interruption with intact tympanic membrane
Ossicular interruption with perforation
Average hearing loss in different lesions: Complete obstruction of ear canal = 30db Perforation of tympanic membrane = 10-40 db Ossicular interruption with intact tympanic membrane= 54db Ossicular interruption with perforation = 38db Closure of oval window can cause 60 db hearing loss