Impedance Audiometry

Impedance audiometry is an objective method based on the measurement of the pressure in the middle ear, stapedius reflexes, and tension of the tympanic membrane and is mostly used with Puretone Audiometry to better diagnose the client’s hearing difficulties.

It is one of the most common and most accurate methods for testing the middle ear as it can help us in diagnosing various disorders of the ear as well as helps an audiologist specifically test an aspect of the middle ear functioning.

An Impedance test can help reveal the following functions of a person’s ears

•  Middle ear pressure and the mobility of middle ear bones.
•  Tympanic membrane movement.
•  Tympanic membrane perforations.
•  Eustachian tube functioning.
•  Can be used in conjugation with other tests to confirm type of hearing loss and other lesions.

Speech Audiometry

Speech audiometry is a fundamental tool in hearing loss assessment. Together with pure-tone audiometry, it can aids in determining the degree and type of hearing loss.

Speech audiometry provides information on word recognition, comfortable sound level about discomfort or tolerance to loud speech stimuli.

Thus, Speech Audiometry gives a real-world perspective of the communication handicap caused by the hearing loss, even more so when it is performed in presence of noise.

Word Recognition Score (WRS) is one of the best test which can be performed to assess the communication deficit caused by the hearing loss. It can also help in providing with a realistic expectation towards the benefit of hearing aids or other amplification devices.

BERA

Is the acronym for the Brainstem Evoked Response Audiometry. The test involves am electrophysiological procedure of procuring electrical responses through surface electrodes which are generated by the auditory nerve and brainstem in presence of sound.

The BERA tests the integrity of the auditory systems, and thus, is one of the most valuable tests to test children who can’t respond to conventional PTA and other difficult to test population.

The BERA can help in both differentially diagnosing and estimating the hearing thresholds of an individual.

ASSR

Is the acronym for the Auditory Steady State Response. It can be thought of as an electrophysiologic response to rapid auditory stimuli. The goal of ASSR is to create an estimated audiogram from which questions regarding hearing, hearing loss, and aural rehabilitation can be answered.

ASSR allows the hearing care professional to create statistically valid audiograms for those unable or unwilling to participate in traditional behavioural tests.

ASSR relies on statistical measures to determine if and where a threshold is present.

OAE (Oto-Acoustic Emissions)

The Oto-Acoustic Emissions (OAE) test is used to find out how well your inner ear, or cochlea, works. It measures otoacoustic emissions, or OAEs. These are sounds given off by the inner ear when responding to a sound.

There are haids cells in the inner ear that respond to sound by vibrating. The vibration produces a very quiet sound that echoes back into the middle ear. This sound is the OAE that is measured.

If you have normal hearing, you will produce OAEs. If your hearing loss is greater than 25–30 decibels (dB), you will not produce these very soft sounds.

This test can also show if there is a blockage in your outer or middle ear. If there is a blockage, no sounds will be able to get through to the inner ear. This means that there will be no vibration or sounds that come back.

Special Tests

Special Tests are used in conjugation with the major tests of hearing to either provide more understanding of the individual’s hearing abilities and difficulties.

SISI Test – The Short Increment Sensitivity Index test is used to determine the perception of loudness increment with increment in amplitude more technically, the test assess recruitment in ears.

TDT Test – Tone Decay Test is used to determine whether the continuous tone being presented decays or not with time which is indicative of auditory nerve dysfunction.

ABLB Test – This test assesses recruitment (abnormal growth in loudness) in cases with asymmetrical/unilateral hearing losses.