Search PubMed⌕ Search

Biomedical subjects

F E Musiek

Publications and source records attributed to F E Musiek.

At least 37 records · Page 2Linked to original sources
PubMed1996

Blockade of opioid-induced changes in auditory function at the level of the cochlea.

OBJECTIVE: We have previously investigated the auditory neural effects of the kappa-opioid receptor agonist, (-)pentazocine. When administered intravenously (i.v.), this drug temporarily alters auditory nerve compound action potential (CAP) amplitudes. To test the hypothesis that the observed neural effects of i.v. (-)pentazocine occur via kappa-receptor interactions within the cochlea, we attempted to block these effects by employing a specific kappa-opioid receptor antagonist applied directly to the cochlear round window (RW) membrane. DESIGN: In 31 normal-hearing, male pigmented chinchillas, amplitude changes in the click-evoked auditory CAP (N1) were tracked at six stimulus intensities during a baseline and a postbaseline period in which i.v. (-)pentazocine (8 mg/kg) was administered. (-)Pentazocine administration was preceded by the delivery to the cochlear RW membrane of an artificial perilymph solution given alone or containing the kappa-opioid receptor selective antagonist, norbinaltorphimine (Nor-BNI), which was administered at two concentrations in separate groups of animals. RESULTS: The amplitude increase in the CAP after (-)pentazocine was significantly reduced when i.v. (-)pentazocine was preceded by RW-administered Nor-BNI (4 mM). CONCLUSIONS: The reversibility of agonist effects by Nor-BNI indicates direct or indirect opioid kappa-receptor-mediated auditory neural effects at the level of the cochlea and suggests a connection between kappa-receptors and auditory neural function.

Animals↗
PubMed1996

Comparison of standard and abbreviated distortion product otoacoustic emissions procedures.

Standard and abbreviated distortion product otoacoustic emissions (DPOAEs) procedures derived using the Grason Stadler Model 60 instrument were compared. The standard and abbreviated procedures were compared at frequencies of 1000, 1250, 1593, 2000, 2531, and 3187 Hz for 48 ears from 28 subjects. The subject pool included individuals with normal hearing and those with sensorineural hearing loss. The abbreviated procedure correlated well with the standard procedure for DPOAE amplitude cross all frequencies tested. The two procedures were also highly similar in categorizing the subjects in regard to normal or abnormal hearing sensitivity. It appears that the shorter analysis time for the abbreviated procedure had little effect on its accuracy. Although the abbreviated procedure has an obvious frequency limitation, it may have some clinical advantages for hearing screening.

Acoustic Stimulation↗
PubMed1995

The auditory brain stem response in patients with brain stem or cochlear pathology.

OBJECTIVE: The purpose of this study was to determine the value, based on true-positive and false-positive rates, of various auditory brain stem response (ABR) indices in discriminating patients with brain stem lesions from patients with cochlear lesions. DESIGN: A factorial design was used in this retrospective study. Receiver operating characteristics (ROC) curves were constructed to analyze the performance of 32 patients with brain stem lesions and 33 patients with cochlear involvement for the absolute latency of wave V; the I-III, III-V, and I-V interwave intervals; the interaural latency difference and the V/I amplitude ratio. Analyzed in the same manner were four combinations of ABR indices. RESULTS: Based on the ROC curves, the clinically most valuable index was the I-V interval, but overall the individual indices showed only moderate sensitivity to brain stem pathology. By combining several indices, the sensitivity to brain stem involvement was improved. However, as expected, the overall false-positive rate also increased. CONCLUSIONS: There is a diagnostic advantage to using more than one ABR index in evaluating patients suspected of having brain stem involvement.

Adolescent↗
PubMed1995

Transient evoked otoacoustic emissions and pseudohypacusis.

The audiologic diagnosis of pseudohypacusis continues to challenge the clinical audiologist. The introduction of otoacoustic emissions (OAEs) to the test repertoire of the audiologist may prove valuable in the evaluation of pseudohypacusis. This report highlights five cases in which transient evoked otoacoustic emissions (TEOAEs) were used to cross-check the validity of subjective audiologic thresholds. Relationships of TEOAEs to other objective measures of audiologic threshold are shown to substantiate the value of the procedure for the diagnosis of pseudohypacusis. Suggestions for the use of OAEs in cases of pseudohypacusis are discussed.

Acoustic Stimulation↗
PubMed1995

"Negative" ABR findings in an individual with a large brainstem tumor: hit or miss?

This case illustrates the importance of determining the precise locus and extent of a lesion when attempting to correlate lesion site with auditory brainstem response (ABR) findings. The failure to document significant ABR findings in an individual with a large mass involving the low brain stem may initially appear to constitute a threat to the sensitivity of the ABR; however, careful review of the radiologic evidence in this case suggests that sensitivity did not suffer, but rather that the specificity of the procedure was upheld. Moreover, the value of electronystagmography (ENG) in the assessment of an individual with a lesion in the region of the low brain stem and severe vestibular symptoms is demonstrated.

Adolescent↗
PubMed1994

Department of Veterans Affairs compact disc recording for auditory perceptual assessment: background and introduction.

Materials for use in auditory perceptual assessment of central auditory problems are widely divergent in quality, usefulness, and complexity. These circumstances make interpreting results a highly provincial affair. Comparison of results between different clinics and laboratories is often difficult or impossible. Norms by which to judge an individual's performance are often applicable for only one version of a given test and may not be appropriate for another version of the "same" test. The pressing need for standardization of a battery of central auditory tasks that is useful in clinical endeavors and in laboratory experiments is obvious. If that battery could encompass a wide range of complexity, and if the items in it were produced with very high quality, then its value would increase. The materials previewed in this introductory article and in seven other articles in this journal edition were developed to address some of these issues. Monotic, diotic, and dichotic materials using speech and tone stimuli were created. They were produced on compact disc under the sponsorship of the Department of Veterans Affairs and with the assistance of many institutions and individuals in the United States. In the articles that follow this one, data generated from their use with young, normal listeners are presented.

Adolescent↗
PubMed1994

Frequency (pitch) and duration pattern tests.

Compact disc versions of the frequency (pitch) and duration pattern tests are reported. Results are similar to previous reports on these tests using taped materials. Mean performance of normal-hearing young adults for both pattern perception tests was approximately 90 percent. There was no effect of the two presentation levels used in this study. The compact disc version of these tests provides a high-fidelity measure of auditory pattern identification that can be administered easily.

Acoustic Stimulation↗
PubMed1994

Effectiveness of transient-evoked otoacoustic emissions (TEOAEs) in predicting hearing level.

The purpose of the present investigation was to (1) determine the short-term test-retest reliability of the transient-evoked otoacoustic emission (TEOAE) parameters of echo level and reproducibility, as produced by the Otodynamic's ILO88 system; and (2) assess the ability of the ILO88 parameters of frequency spectrum, echo level, and reproducibility to identify ears with sensorineural hearing loss. Our results show that the short-term test-retest reliability for both echo level and reproducibility is excellent, reflecting the stability of TEOAEs and the low measurement error associated with the procedure for obtaining TEOAEs. The data suggest, however, that frequency-specific hearing levels (HLs) cannot be accurately predicted from the analogous frequencies depicted in the frequency spectrum produced by the ILO88 system. Although frequency-specific HLs cannot be predicted from the frequency spectrum, the parameters of echo level and reproducibility will clearly separate individuals with HLs < or = 20 dB from individual with HLs > 20 dB for the octave frequencies of 500-4000 Hz. An echo level of < 6 dB and/or a reproducibility value of < 70 percent are associated with HLs > 20 dB between 500 and 4000 Hz. The combination criterion of an echo level of < 6 dB and a reproducibility value of < 70 percent appears to be a suitable screening method for identifying adult ears with an average HL of > 20 dB.

Acoustic Stimulation↗
PubMed1993

Loudness discomfort level and reliability as a function of instructional set.

Loudness discomfort levels (LDLs) for a 12-speaker babble were measured in 20 subjects with normal hearing sensitivity for two instructional sets, listening in the sound field. One instructional set asked the listener to indicate when they would choose 'not to listen for any period of time'. The second instructional set asked the listeners to indicate when they 'would choose not to listen for 15 minutes or longer'. A simple up-down adaptive procedure was used to measure LDLs. Data were gathered on both instructional sets for all listeners. LDLs for each instructional set were repeated on four separate occasions within a range of 1-3 weeks. The average LDLs for the instructions utilizing the criterion of choosing not to listen for any period of time were 9 dB higher than the criterion of choosing not to listen for 15 minutes or longer. The reliability of LDLs for both instructional sets was high, ranging from correlations of 0.90-0.97 for the criterion of choosing not to listen for any period of time, and ranging from correlations of 0.62-0.89 for the criterion of listening for 15 minutes or longer. The criterion of choosing not to listen for any period of time resulted in slightly more reliable measures. These results support the importance of considering the instructions given to a person to measure LDLs, and hence for where to set the saturation sound pressure level of a hearing aid. Also, with appropriate methods, LDLs can be reliably measured in the sound field.

Acoustic Stimulation↗
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↗