Brief-tone audiometry with normal, cochlear, and eighth nerve tumor patients.
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Audiometry↗
Biomedical subjects
D Noffsinger
Publications and source records attributed to D Noffsinger.
Auditory and vestibular aberrations in multiple sclerosis.
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Adult↗
Value of special auditory tests in the latero-medial inferior pontine syndrome.
Results from a special battery of auditory tests are used to document, for the first time, recovery from a total unilateral hearing loss occurring as part of a latero-medial inferior pontine syndrome. Although sensitivity for pure tones and speech was regained within two months of onset, definite retrocochlear signs persisted for nine months. The tests which best demonstrated the lingering retrocochlear abnormality were binaural masking level difference procedures for 500 Hz pure tones and speech and examination of the amplitude of the acoustic reflex over a ten second time period. The relative sensitivity of other speech and pure tone tasks in detecting the retrocochlear problem is detailed.
Animals↗
Masking level differences for cochlear and brain stem lesions.
Masking level differences (MLD) for 500 Hz pure tones and for spondees were obtained from 48 subjects. Twelve were without otologic or neurologic complaints (normal), 12 had high frequency, noise-induced hearing losses, 12 were diagnosed otologically as having Ménière's disorder, and 12 had neurologically diagnosed central nervous system (CNS) disorders. Results indicated that high frequency, noise-induced hearing losses do not affect MLD for 500 Hz stimuli, but do diminish the size of MLD for speech. Masking level differences for both 500 Hz and spondees were decreased for the Ménière's disorder group. The group of patients having CNS disorders attributed to multiple sclerosis, to inflammatory lesion of the pons, to degenerative processes of the cerebellum and adjacent nervous tissue, or to brain stem cerebrovascular accident had normal hearing according to conventional pure tone and speech testing, but attained smaller than normal MLD for 500 Hz and spondees. These findings agree closely with results obtained in an earlier study and continue to suggest that, given normal peripheral auditory function, MLD tests may have unique value in detection of subtle lesions of the central auditory nervous system.
Auditory Perception↗
Speech discrimination in quiet and in white noise by patients with peripheral and central lesions.
Speech-discrimination scores in quiet and in white noise (O dB S/N ratio) were obtained from six groups of subjects. Differences of 40% or more between scores in quiet and in white noise were observed for less than 1% of the normal ears tested but were found for 8.0% of ears with noise trauma, 48% of ears with Meniere's disease, 62% of ears with subsequently surgically confirmed 8th-nerve tumors, 14% of ears of patients with multiple sclerosis, and 42% of ears contralateral to the lesion in patients with temporal-lobe damage.
Acoustic Stimulation↗
Masking level differences encountered in clinical populations.
Methods for measuring masking level differences (MLDs) at 500 Hz and for spondees were used with 290 subjects: 50 persons with normal hearing and 240 patients with various diseases. Of particular interest was whether techniques currently in clinical use could be used with ease, dispatch, and profit in determining MLD size. The methods selected, which were variations of Békésy audiometry and speech reception threshold procedures, proved clinically feasible. Results revealed differences in behavior from one group of subjects to another. Although MLDs were not affected by cortical lesions, they were very often abnormally small for patients with eight-nerve tumor, Meniére's disease, or multiple sclerosis. The high incidence of abnormally small MLDs in populations with normal sensitivity to pure tones and speech but with evidence of subcortical central lesions, such as patients with multiple sclerosis, suggests that the MLD tasks can be of diagnostic value in detecting retrocochlear lesions. However, in persons with hearing loss or significant interaural differences in threshold sensitivity, or both, the MLD tests are not always reliable in differentiating cochlear from retrocochlear disease.
Acoustic Stimulation↗
A jugular foramen schwannoma simulating an acoustic tumor with recovery of retrolabyrinthine cochleovestibular function.
Our literature review has tabulated 33 jugular foramen neuromas that appeared either as a neurologic "syndrome of the jugular foramen" like a glomas tumor, or similar to an acoustic tumor. The few posterior fossa tumors involving the eighth nerve or encroaching upon it that have been removed and resulted in cochleovestibular preservation or recovery have been reviewed. A rare case of jugular foramen schwannoma with cochleovestibular preservation after total removal has been extensively studied with preoperative and postoperative cochleovestibular tests.
Adult↗
Performance by cortical lesion patients on 40 and 60% time-compressed materials.
Tape recordings of time-compressed (40 and 60%) monosyllables were administered to 11 patients with diffuse unilateral temporal lobe lesion, 4 hemispherectomy patients, and 16 patients with discrete unilateral temporal lobe lesion. Time compression was accomplished with the Fairbanks electromechanical apparatus, which allowed temporal compression but did not introduce frequency distortion. The results revealed that with 60% time compression, all patients with diffuse unilateral cortical lesion showed breakdown of speech discrimination in the ear contralateral to the lesion. Patients with discrete unilateral cortical lesion generally did not demonstrate breakdown with the 60% time-compressed materials.
Audiometry↗