| auditory brainstem response audiometry | An electrophysiologic measure of auditory function utilizing responses produced by the auditory nerve and the brainstem to repetitive acoustic stimuli. (05 Mar 2000) |
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| auditory canal | The passage leading inward through the tympanic portion of the temporal bone, from the auricle to the tympanic membrane; it consists of a bony (inner) portion and a fibrocartilaginous (outer) portion, the cartilaginous external acoustic meatus. Synonym: meatus acusticus externus, acoustic meatus, antrum auris, auditory canal, external auditory meatus. (05 Mar 2000) |
| auditory capsule | The cartilage that, in the embryo, surrounds the developing auditory vesicle and develops into the bony labyrinth of the inner ear. (05 Mar 2000) |
| auditory cortex | Area of the temporal lobe concerned with hearing. (12 Dec 1998) |
| auditory diseases, central | Diseases of the auditory pathways from the bulbar cochlear nuclei to the auditory cortex in the temporal lobe. Structures involved include the medial and lateral lemnisci, inferior colliculus, and the medial geniculate nucleus. (12 Dec 1998) |
| auditory evoked potentials | <investigation> A special neurologic test, known as brainstem auditory evoked potentials, which measures the brain and brainstem nervous response to auditory stimulation. A test used to evaluate neurologic integrity and hearing in newborns. Can be used in the evaluation of stroke, acoustic neuroma, Meniere's disease and multiple sclerosis (27 Sep 1997) |
| auditory fatigue | Loss of sensitivity to sounds as a result of auditory stimulation, manifesting as a temporary shift in auditory threshold. The temporary threshold shift, tts, is expressed in decibels. (12 Dec 1998) |
| auditory field | The space included within the limits of hearing of a definite sound, as of a tuning fork. (05 Mar 2000) |
| auditory ganglion | An elongated ganglion of bipolar sensory nerve cell bodies on the cochlear part of the vestibulocochlear nerve in the spiral canal of the modiolus; each ganglion cell gives rise to a peripheral process that passes between the layers of the bony spiral lamina to the organ of Corti, and a central axon that enters the hindbrain as a component of the inferior (cochlear) root of the eighth nerve. Synonym: ganglion spirale cochleae, auditory ganglion, cochlear ganglion, Corti's ganglion, spiral cochlear ganglion. (05 Mar 2000) |
| auditory hairs | Cilia on the free surface of the auditory cells. (05 Mar 2000) |
| auditory hallucination | A symptom frequently observed in a schizophrenic disorder consisting, in the absence of an external source, of hearing a voice or other auditory stimulus that other individuals do not perceive. (05 Mar 2000) |
| auditory hyperesthesia | Hyperacusia Abnormal acuteness of hearing due to increased irritability of the sensory neural mechanism. Synonym: auditory hyperesthesia. Origin: hyper-+ G. Akousis, a hearing (05 Mar 2000) |
| auditory lemniscus | A bundle of ascending fibres that originate from the cochlear and auditory relay nuclei of the rhombencephalon, enter the trapezoid body, a transverse fibre stratum in which about half their number decussate, and from here turn rostrally along the lateral side of the spinothalamic tract; in the midbrain, it arches dorsally and enters the inferior colliculus in which all of its fibres terminate; the auditory pathway is transsynaptically extended from here by the brachium of the inferior colliculus to the medial geniculate body of the thalamus, from which in turn the auditory radiation leads to the auditory cortex; intercalated in the trapezoid body and along the ascending trajectory of the lemniscus are several cell groups in which part of the fibres synapse. Synonym: lemniscus lateralis, acoustic lemniscus, auditory lemniscus, auditory tract, lateral fillet. (05 Mar 2000) |
| auditory localization | In sensory psychology, the naming or pointing to directions from which sounds emanate. (05 Mar 2000) |
| auditory nerve | <anatomy, neurology> Cranial nerve VIII is responsible for the sense of hearing and balance (body position sense). Lesions of the eighth nerve can result in deafness, tinnitus, dizziness, vertigo and vomiting. (27 Sep 1997) |