What does a Type As tympanogram indicate?

A Type As tympanogram indicates reduced compliance with normal pressure. This type of tympanogram is characterized by a peak that is present but is lower than what is typically expected at the normal range of compliance. The "S" in Type As signifies "shallow" compliance, suggesting that the movement of the tympanic membrane (eardrum) is restricted, which can indicate stiffness in the middle ear system.

When a tympanogram shows normal pressure but with reduced compliance, it often points towards conditions such as otosclerosis or the presence of fluid in the middle ear that is affecting the mobility of the ossicular chain, thereby leading to less than optimal movement of the eardrum despite there being normal air pressure in the ear canal.

Understanding tympanogram types is essential in audiology as it helps clinicians diagnose the status and functionality of the middle ear.