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Biomedical subjects

F E Musiek

Publications and source records attributed to F E Musiek.

At least 19 recordsLinked to original sources
PubMed1992

Recognition of distorted speech in children with and without learning problems.

The effects of listening to time-compressed speech alone and in a competing babble, with speech in and out of phase between ears, were studied in 10 children with no apparent auditory or learning problems and in 10 children with learning disabilities and a suspected central auditory processing problem. The children ranged in age from 8 to 10 years. Both groups showed significant decreases in speech recognition when speech was compressed at a rate of 60 percent as compared with recognition of normal-rate speech. However, the children in the learning disabilities group showed a greater decrease. Listening to time-compressed speech in a binaural mode resulted in better speech recognition than in a monaural mode for both groups. When speech was shifted 180 degrees out of phase between ears, both groups demonstrated a release from masking for speech presented at a fast rate (60% compression), but the normal group had a greater release from masking than the learning disabilities group. Also, the learning disabilities group did not show a release from masking for normal-rate speech (0% compression). When both groups listened to speech that had been compressed and presented in a babble, their performance supported a multiplicative distortion theory, with children in the learning disabilities group showing a slightly greater multiplicative effect than the children with no apparent problems. The results support the necessity of binaural hearing to maximize auditory performance in difficult listening situations in two populations of subjects.

Auditory Diseases, Central↗
PubMed1992

P300 results in patients with lesions of the auditory areas of the cerebrum.

Auditory P300 event-related potentials were obtained at C3 and C4 recording sites from 20 patients with cerebral lesions that affected auditory areas of the brain. The patient group was matched for age and hearing sensitivity to a control group of 20 subjects. There were significant differences between the two groups for both latency and amplitude of the P300. Eight patients demonstrated an absent P300 for at least one recording condition while all subjects in the control group had readable P300s in all recording conditions. A subset of patients with lesions limited to one hemisphere showed no laterality effects for amplitude or latency of the P300 for the ear or electrode that was either ipsilateral or contralateral to the lesion. In comparison to the P2 evoked potential, the P3 was more sensitive to neurologic lesions.

Adolescent↗
PubMed1991

Effects of opioid be drugs on auditory evoked potentials suggest a role of lateral olivocochlear dynorphins in auditory function.

Multiple gene products of opioid peptide families (e.g., enkephalins, dynorphins) with differing opioid receptor specificities are present within olivocochlear efferent terminals. Enkephalins activate mu- and delta-opioid receptors, and are generally inhibitory in the nervous system, and dynorphins are kappa-receptor agonists, which may be excitatory to postsynaptic neurons. We have examined the effects of intravenously administered opioid agonists and antagonists on click-evoked N1 and N2 amplitudes and latencies of the compound action potential in the chinchilla recorded at the round window. Parenteral administration of the opioid receptor antagonist naloxone or the potent mu-receptor agonist fentanyl did not alter N1 and N2 amplitudes or latencies. The kappa-receptor agonist, mu-receptor antagonist pentazocine caused marked increases in N1 and N2 amplitudes over baseline values at threshold intensities. These effects were not abolished by naloxone. No effects were seen on the cochlear microphonic, supporting a site of action of these effects at the lateral olivocochlear efferent terminals on auditory nerve dendrites under inner hair cells. Similar results were obtained when far field auditory evoked responses were recorded. Results were obtained under ketamine/pentobarbital anesthesia, which provided stable recording baselines in contrast to tiletamine/zolezepam/pentobarbital, with which an upward drift in auditory potentials was observed. This stimulatory action of kappa-agonists on auditory-evoked potential amplitudes appears to represent a physiological role of the lateral olivocochlear efferent innervation. The different neurotransmitters of the olivocochlear efferents (e.g. enkephalins, dynorphins, acetylcholine) may have antagonistic actions on auditory potentials, as may the lateral and medial systems themselves.

Animals↗
PubMed1991

Repair of a cerebrospinal fluid perilymph fistula primarily through the middle ear and secondarily by occluding the cochlear aqueduct.

A 35-year-old man had a 5-year history of fluctuating hearing loss in his only hearing ear. History and diagnostic tests indicated a perilymph fistula, a diagnosis subsequently confirmed by exploration. Primary and secondary repairs temporarily ameliorated symptoms. A spinal fluid to middle ear fluid pathway was identified by radioactive tracer. A patent cochlear aqueduct indicated on computed tomography scan was found and repaired through a posterior cranial fossa approach. Hearing was preserved, remaining relatively stable during the 2-year follow-up period.

Adult↗
PubMed1991

Click evoked otoacoustic emissions in adult subjects: standard indices and test-retest reliability.

The present study was designed to evaluate transiently evoked otoacoustic emissions in an otologically normal adult population. Using the ILO 88 Otodynamic Analyzer, the recorded otoacoustic emission responses were analyzed for five parameters. Considering the variability of instrumentation and technique in otoacoustic emission testing, we have defined a normative data pool using standard commercially available testing equipment. These data should facilitate comparison with data acquired in various pathologic states. The test-retest validity of this procedure also was evaluated and was found to be high. Use of click evoked otoacoustic emissions, with some caveats, appears to be a promising technique for further research into the assessment of normal/abnormal cochlear function.

Acoustic Stimulation↗
PubMed1991

SN10 auditory evoked potential revisited.

The slow brainstem response (SN10) was originally described as a slow negative wave occurring at a latency of 10 msec post stimulus onset. In the late 1970s and early 1980s it was considered to be promising for estimating hearing thresholds at low frequencies. However, there have been controversies regarding waveform description, recording stimulus parameters, and factors affecting the response. Consequently, the SN10 has not become a popular clinical test for estimating hearing thresholds electrophysiologically. However, recent observation of ABR waveforms using low-frequency stimuli and broad-band filtering indicate that the negative wave after wave V can be highly identifiable. This wave in many instances is the SN10. Therefore, this article was designed to review various aspects of the SN10 to make clinicians more aware of its possible applications in estimating low-frequency hearing thresholds.

Audiometry, Evoked Response↗
PubMed1991

Proposed screening test for central auditory disorders: follow-up on the dichotic digits test.

A follow-up report on the dichotic digits test (DDT) demonstrates that this procedure has good sensitivity to central auditory nervous system (CANS) pathology while remaining relatively resistant to mild-to-moderate high-frequency cochlear hearing loss. The DDT's test-retest reliability and short administration time make it an attractive screening procedure for CANS disorders.

Adolescent↗
PubMed1990

An introduction to the functional neurochemistry of the auditory system.

Neurochemistry of the auditory system has become one of the fastest growing areas in the study of audition. Many recent advances have implications for not only the basic auditory researcher but also the clinician. This article introduces some of the fundamentals of auditory neurochemistry as well as some recent developments. Also highlighted are some of the studies that appear to have current and future clinical significance.

Animals↗
PubMed1990

Canal electrode electrocochleography in patients with absent wave I ABRs.

Fifteen patients (23 ears) who demonstrated no recordable wave I at the time of clinical auditory brainstem response testing were subsequently retested under three auditory brainstem response-electrocochleography conditions. One condition was the traditional auditory brainstem response, another was the auditory brainstem response with electrocochleography filtering, and the third was an electrocochleographic condition using a canal electrode (Tiptrode). The electrocochleographic recording condition provided more readable wave I responses than the other conditions. In addition, the electrocochleographic condition provided wave I amplitudes that were greater than those of the traditional auditory brainstem response. The later waves of the auditory brainstem response (III and V) were similar in wave presence amplitudes and latencies for all three test conditions.

Adult↗
PubMed1990

Duration pattern recognition in normal subjects and patients with cerebral and cochlear lesions.

Three groups of subjects were tested on a duration pattern recognition task. The groups included normal subjects, subjects with cochlear hearing loss, and subjects with lesions involving but not limited to the auditory areas of the cerebrum. Results indicated no significant difference in pattern recognition between the normal subjects and subjects with cochlear hearing loss. However, the subjects with cerebral lesions performed significantly more poorly than either the normal subjects or those with cochlear hearing loss. In comparing pattern recognition performance for the ears ipsilateral and contralateral to the lesioned hemispheres no differences were noted. Rather, when a central lesion was present, both ears generally yielded abnormal scores.

Adult↗
PubMed1990

Improvement of central auditory function after partial temporal lobectomy in a patient with seizure disorder.

This case study reports the auditory findings in one patient with left temporal lobectomy. Behavioral and electrophysiologic central auditory tests were administered just before and 1 week after surgical removal of the left anterior temporal lobe, including the amygdala and portions of the hippocampus. The dichotic digits test and late auditory evoked potentials with P-300 showed marked improvement postoperatively, consistent with improved central auditory function. Postoperative behavioral results on the dichotic digits test are consistent with anatomic evidence that there are few, if any, auditory connections to the anterior temporal lobe. Although electrophysiologic recordings improved postoperatively, they are still considered abnormal. This case study illustrates the use of both behavioral and electrophysiologic procedures for monitoring central auditory function.

Adult↗
PubMed1990

Asymmetries of the auditory areas of the cerebrum.

A total of 29 human cadaver brains were examined for asymmetries of the left and right Sylvian fissure, Heschl's gyri, and planum temporale. The mean lengths of these structures were all significantly greater on the left side than on the right. There was considerable morphologic variability in these structures as evidenced by the number of Heschl's gyri that ranged from one to three per hemisphere in different brains, although there was no significant asymmetry in the number of Heschl's gyri in individual brains. Asymmetry of the Sylvian fissure was correlated with the greater length of the planum temporale on the left side. Although it is well known that the planum temporale is larger in the left hemisphere than in the right, little has been reported on Heschl's gyri in this regard. It is possible that asymmetries in higher auditory and language function may be attributable to anatomic asymmetries of not only the planum temporale but also Heschl's gyri.

Aged↗
PubMed1990

Objective tinnitus of vascular origin with hearing improvement after treatment.

Objective tinnitus occurs as a result of muscular contraction or vascular pulsations. The literature is reviewed and we present two case reports of vascular objective tinnitus and its diagnostic and therapeutic modalities. One patient was treated with embolization alone; the other, with embolization and surgical ligation. Both patients achieved an improvement in sensorineural hearing thresholds in their affected ears; one patient experienced an improvement in speech reception threshold of 30 decibels. Measures useful to diagnosis and evaluation of therapy and reasons for the observed improved hearing thresholds are discussed.

Adult↗
PubMed1989

The dichotic rhyme task: results in split-brain patients.

Monosyllabic rhyme words were dichotically presented to normal and complete split-brain subjects. In the normal adult population, only one of the words in the dichotic condition was identified. Hence, normal performance was about 50%, with a small but significant right-ear advantage. The split-brain patients yielded the expected marked left deficit, as seen on other dichotic speech tests, and demonstrated a right-ear enhancement, producing a large interear difference. This right-ear enhancement on the dichotic rhyme task (DRT) may suggest a release from central auditory competition in the left hemisphere. The dichotic rhyme task's normative data results and sensitivity to lack of callosal transmission make it worthy of further clinical and basic research.

Adolescent↗
PubMed1989

The auditory brain stem response interaural latency difference (ILD) in patients with brain stem lesions.

The ABR interaural latency difference (ILD) from 15 patients with brain stem lesions was compared to the ILDs from patients with VIIIth nerve tumors, cochlear pathology, and a normal control group. All patients in the study had to meet the criteria of bilaterally symmetrical hearing for pure-tone thresholds in order to offset the effect of hearing loss on the ILD. Although the ILDs for the brain stem lesion group were larger than for the cochlear or normal groups, they were significantly smaller than for the VIIIth nerve tumor group. It appears that the ILD is not as sensitive a measure for detecting brain stem involvement as VIIIth nerve tumors.

Adult↗
PubMed1989

Electrophysiologic and behavioral auditory findings in multiple sclerosis.

An auditory test battery composed of seven behavioral and electrophysiologic measures, in addition to pure tone testing, was administered to 33 subjects with definite multiple sclerosis. More than 40% of the subjects with normal peripheral hearing presented with subjective complaints of hearing difficulties. Auditory brainstem response (ABR) was found to be the most sensitive individual test in detecting central auditory dysfunction. Further analyses suggested that the combination of ABR and masking level difference (MLD) tests was essentially as effective as the entire test battery in detecting dysfunction in these subjects. Dichotic speech measures, unlike other tests, showed a definite laterality effect with the left ear consistently poorer, possibly reflecting interhemispheric involvement.

Adult↗