The ABR is a non-invasive, objective test, which can be used as an estimate of hearing loss or for assessment of neurological function. The responses from the inner ear and brainstem, which are detected by the electrodes, are amplified, averaged, and stored in the computer. Sounds called "clicks" are presented at various loudness levels and at different rates. The patient does not respond to the sounds and can even sleep during the test. Each ear is tested separately with an earphone. The ABR is recorded from scalp electrodes placed on the head, forehead, and earlobes or mastoids. Auditory evoked potentials which occur in the first ten milliseconds after the presentation of a sound originate in the part of the brain called the brainstem and are called the AUDITORY BRAINSTEM RESPONSE (ABR). These minute voltage variations in response to sounds are called AUDITORY EVOKED POTENTIALS. When a sound is heard, we expect some change in the electrical activity of the brain. Hearing involves not only the ear, but also the brain. OAEs is a non-invasive objective test, which contributes to the detailed assessment of the auditory system. In addition, presence of OAEs tends to rule out any abnormality in the conductive pathway (i.e. Results of this testing can indicate presence or absence of hearing loss and the type of hearing loss. During this test, a soft tip is placed in your ear canal and you will hear a series of sounds. Otoacoustic emissions (OAEs) are sounds produced by the cochlea (inner ear) either spontaneously or in response to sound. It is also an important test in detecting problems in the auditory pathway. Acoustic reflex test results provide valuable information regarding the type and severity of your hearing loss and the possible cause of your hearing loss. The equipment measures the presence or absence of the reflex. The acoustic reflex is an involuntary contraction of the muscle attached to one of the small bones behind the eardrum.ĭuring this test you will hear a series of loud sounds of varying pitches in each ear. Acoustic Reflex TestingĪcoustic reflex testing is completed for each ear following tympanometry. Abnormal eardrum movement may affect hearing ability. By recording the response of the eardrum to the changes in air pressure, the audiologist can determine if the eardrum is moving normally. You will hear a buzzing sound and feel some pressure changes in your ear. The clinician will place a soft rubber tip in your ear canal, which must fit snugly in order to begin the test. TympanometryĪnother important part of audiological assessment is tympanometry, which measures the mobility of the eardrum. ![]() Speech audiometry is used for the evaluation of a) hearing sensitivity, b) speech perception ability and c) site of lesion testing. Word recognition testing measures how well the individual understands speech stimuli. Speech recognition thresholds are determined for each ear and represent the lowest hearing level at which speech can barely be understood. Speech audiometry includes speech recognition thresholds, word recognition testing, and sensitized speech testing (filtered, compressed, speech in noise, etc.). Results of pure tone audiometry indicate the presence or absence of hearing loss, the type of hearing loss, and the degree of hearing loss. These thresholds are recorded on an audiogram, which indicates the softest level you hear each pitch for each ear. The responses are called thresholds and represent the levels at which tones are barely audible. You will be asked to respond each time you hear the tone by pushing a button or raising your hand. The test signal can be presented through earphones through a small vibrator, which delivers the tones through the vibration of the skull or through loud speakers. During this test, the clinician uses an audiometer to generate auditory signals of different pitches (frequencies) or "pure tones". Pure tone audiometry is administered while you are seated in a sound isolated booth. The clinician will also note the amount of earwax and/or anything unusual in the ear canal. ![]() The clinician will be looking at the condition of the ear canal and eardrum. Before beginning audiometric testing, the audiology clinician will look into your ear canals with an otoscope (an instrument used to direct light into your ear canal).
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