Impedance Audiometry/Tympanometry Test

Impedance Audiometry, which is sometimes also referred to as Tympanometry, is primarily used to assess functioning of the ear drum, tympanic membrane and middle ear via Tympanometry.Secondly, the hearing test is used to evaluate acoustic reflex pathways including the cranial nerves and auditory brainstem.

It allows the audiologists to assess how the eardrum vibrates when sound strikes and how well the nearby bones transmit such vibrations.

Why is Impedance Audiometry Required?

Essentially, impedance audiometry is not a hearing test and does not measure patient’s auditory sensitivity directly. It is a measure of energy transmission through the middle ear and is used to detect the pressure changes in the middle ear and is always performed in conjunction with Pure Tone Audiometry Test.

Indications

Impedance Audiometry can be used to diagnose the below mentioned disorders in the auditory systems:

• Indirect hearing loss
• Middle ear effusion
• Eardrum perforation
• Tympanosclerosis
• Glue ear
• Hypermobile eardrum
• Acoustic neuroma
• Otosclerosis
• Brainstem disorders
• Facial nerve dysfunction

Different treatments under Impedance Audiometry

Determining the functioning of the central and peripheral auditory systems, there are several acoustic immittance treatment procedures. The most important of them are as follows:

• Tympanometry: It helps in detecting fluid in the middle ear, wax blockage within the ear canal and perforation of the eardrum. In general terms, the test measures the overall mobility of the eardrum.
• Acoustic Reflex Thresholds: Acoustic Reflex measures the contraction of the stapedius muscle, which occurs in individuals as a response to the noise directed towards the auditory pathway. The hearing test detects the probable location of hearing disorder and is generally performed after Tympanometry.
• Static Acoustic Impedance: This test evaluates the physical volume of air in a patient’s ear canal and is often used to assess the openness of ventilation tubes and diagnose perforated eardrum.