Diagnostic Audiometric Tests

Diagnostic Audiometric Tests

Comprehensive audiometry includes a number of tests which help the audiologist assess the type and degree of a patient’s hearing impairment These tests can be performed for almost any patient. These tests include:

Pure Tone Audiometry

Tests using pure tone signals determine a patient’s hearing sensitivity for the range of typical everyday sounds, particularly speech sounds. During pure tone testing, the patient is seated in a sound treated room. He or she listens for discreet tones under earphones. If warranted, the tests are repeated with a bone conduction headphone, which is used to confirm or rule out a middle ear component of hearing impairment.

Speech Audiometry

Speech testing includes detection and discrimination tasks. Speech discrimination is useful in determining whether the patient processes speech sounds normally. Good speech discrimination scores typically indicate a patient can benefit from amplification, if warranted.

Immittance Audiometry

Immittance testing is used to determine resistance in the middle ear system. These tests include tympanometry and acoustic reflexes. Tympanometry measures the flexibility of the eardrum (tympanic membrane), and acoustic reflexes help assess both nerve conduction and the middle ear system. Immittance tests help confirm the presence of middle ear fluid, a functioning ventilation tube, or a perforation.

Advanced audiological tests include Auditory Evoked Brainstem Response (ABR), Evoked Otoacoustic Emissions (OAEs) and Electrocochleography (ECoG). These are termed “site of lesion” tests because they are used to determine whether a specific hearing loss is sensory (cochlear) or neurological in nature.

Evoked Otoacoustic Emissions (OAES)

OAE tests assess the function of the cochlea by relying on a natural phenomena, emissions, which occur in normally functioning ears. When a normal cochlea is stimulated with sound, a (very weak) signal, the emission, is returned from the inner ear through the tympanic membrane. This emission can be recorded by special microphones placed in the ear canal.

Electronystagmography (ENG)

ENG testing involves a series of tests to assess balance function. The tests are designed to isolate abnormal dizziness, if possible, to either the inner ear(s) or central nervous system.