Tympanograms in various diseases

Type A: Normal tympanic membrane (TM) mobility. Type B: Flat tympanogram associated with fluid or perforation (will have large volume). Type C: Negative middle ear pressure such as from a retracted TM. Type AS: Very stiff noncompliant TM associated with TM sclerosis or otosclerosis. Type AD: Hypermobile usually associated with ossicular discontinuity.