Which of the following is not a cause of conductive hearing loss-

Ans. is 'c' i.e., Presbycusis Causes of conductive deafnessCongenital causeso Meatal atresiao Fixation of stapes footplateo Fixation of malleus heado Ossicular discontinuityo Congenital cholesteatomaAcquired causeso External ear:# Any obstruction in the ear canal, e.g. wax, foreign body, furuncle, acute inflammatory swelling, tumor, atresiao Middle ear :# Perforation of tympanic membrane (traumatic or infective)# Fluid in middle ear (ASOM, serous otitis media or haemotympanum)# Mass in middle ear (tumors)# Disruption of ossicles (Trauma, CSOM, cholesteatoma)# Fixation of ossicles (otosclerosis, tympanosclerosis, adhesive otitis media)# Eustachian tube blockage (retracted tympanic membrane, serous otitis media)