Biomedical subjects

H N Gutnick

Publications and source records attributed to H N Gutnick.

10 recordsLinked to original sources

PubMed1991

Cochlear versus retrocochlear presbyacusis: clinical correlates.

This study reviews audiologic findings on cases of hearing-impaired elderly adults who were matched on the basis of peripheral hearing loss and who were divided into cochlear and retrocochlear groups on the basis of auditory brain stem response (ABR) test results. ABR test results were compared to other audiologic test results that included: (1) word-recognition scores and performance-intensity functions of phonetically balanced word lists; and (2) performance-intensity functions of Synthetic Sentence Identification lists with ipsilateral competing messages. The results of this study indicate that the retrocochlear group performed less favorably than the cochlear group on speech measures known to be sensitive to a retrocochlear site of disorder. This study further emphasizes the complexity of presbyacusis by demonstrating that peripheral hearing loss, alone, cannot account for the totality of the auditory problems that are encountered by elderly listeners.

Aged↗

PubMed1990

Comparison of two cognitive bedside screening instruments in nursing home residents: a factor analytic study.

The Mini-Mental State Examination (MMSE) and the Blessed Orientation-Memory-Concentration test (BOMC) were each administered to 110 nursing home residents. The correlation between the MMSE and BOMC's total score was -.79. Maximum likelihood factor analysis revealed a two-factor structure, consisting of memory-attention and verbal-comprehension factors that were highly correlated (.69). The results suggest that the somewhat longer MMSE may be preferred for bedside mental status testing, as it clearly measures an additional dimension of cognitive ability, while the BOMC is primarily a unidimensional test. The theoretical and clinical implications of bedside mental status testing of elderly patients are discussed.

Aged↗

PubMed1990

A model of waveform reliability in facial nerve electroneurography.

This study identifies four factors that should be considered when evaluating the reliability of new testing methods in facial nerve electroneurography (ENOG): (1) waveform peak-to-peak amplitude; (2) response variability; (3) statistical significance of day-to-day test/retest differences; and (4) waveform morphology. These factors were applied to data gathered on seven normal subjects who had three trials of facial-nerve ENOG on three separate test days in order to determine an optimal recording electrode montage. Both bipolar and monopolar recording-electrode montages were used on the nasal alae and on the nasolabial crease. Resultant peak-to-peak amplitudes of combined motor action potentials were recorded and measured using a clinical evoked-potential instrument. A biphasic waveform shape with optimal peak-to-peak point rather than the nasolabial crease. The contribution to the assessment of response reliability of each of the four factors is discussed.

Action Potentials↗

PubMed1990

Waveform morphology and amplitude variability in facial-nerve electroneurography.

This study assesses the effect of using bipolar recording electrodes in the nasolabial crease versus using monopolar recording electrodes in the crease and on the nasal alae. Seven normal patients had three trials of facial-nerve electroneurography on three separate test days. Peak-to-peak amplitudes of combined motor action potentials were measured; amplitude variability was not affected by the measurement site. A biphasic waveform shape was most consistently obtained by using the nasal alae as the recording point rather than the nasolabial crease. We hypothesize that alar electrodes primarily detect combined motor action potential activity from relatively synchronous, fast-conducting facial-nerve fibers, while the combined motor action potential detected by electrodes in the nasolabial crease reflect a relatively complex summation of both fast and slow fibers.

Action Potentials↗

PubMed1989

Measurement and prediction of hearing loss in a nursing home.

The purpose of this study was to evaluate the abilities of three paper-and-pencil tests to predict pure-tone hearing loss of nursing home residents. The three tests used were the staff version of the Nursing Home Hearing Handicap Index and two tests of mental status, the Mini Mental State and the Short Orientation-Memory-Concentration Test. Testing was done on the residents (n = 122) of a long-term, intermediate-care nursing home. In general, the residents who passed the hearing test (using a 40 dB HL criterion) performed better on all three tests than did the residents who failed the hearing test and the residents who could not be tested. The results of discriminant analyses showed that the factor of age predicted hearing loss with a sensitivity of 93% and a specificity of 35%. The factor of age in combination with question 4 of the SOMCT and question 10 of the NHHI improved specificity to 53%.

Acoustic Impedance Tests↗

PubMed1984

Effect of psychophysical backward masking on human brain-stem responses (ABR).

A backward-masking (BWM) paradigm was used to obtain measurements on 4 normal young adults of psychophysical BWM and of the analogous electrophysiological masking from human auditory brain-stem responses. The same stimuli and Ss were used in both experiments. Psychophysical BWM was determined to a 100-musec click masked by a 100-msec white noise after time delays of 1, 5, 10, 25, and 100 msec and at noise masker levels of 50, 65, and 80 db SPL. As previously demonstrated, more psychophysical BWM occurs at short delta ts (1 to 10 msec) than at longer delays and masked thresholds are greater as masker level increases. In the electrophysiological experiment, using delta ts = 1, 5, and 10 msec, the extent to which wave V latency was affected by the following masker was determined for various experimental conditions. Wave V latency increased with a decrease in delta t, for maskers above probe level, except that latency was not significantly affected by any masker level at delta t = 10 msec.

Acoustic Stimulation↗

PubMed1982

A model for predicting clinically relevant group differences of open-response tests.

A comparison is made between testing for differences in group means and testing to assign an individual subject to one of two populations. A distinction is made between sample means of speech-discrimination tests which are statistically different and clinically useful speech-discrimination tests for properly classifying an individual. The probabilities of misclassification are discussed.

False Negative Reactions↗

PubMed1982

Consonant-feature transmission as a function of presentation level in hearing-impaired listeners.

Normal-hearing listeners and listeners with a high-frequency sensorineural hearing loss identified 17 consonants as part of a consonant-vowel syllable with /a/ or /i/ as the vowel. The syllables were set at presentation levels of 10 to 65 dB re thresholds at 1000 Hz. The performance for the consonants comprising each of 11 a priori acoustic-phonetic features improved directly with increases in presentation level for both subject groups, but was better in the /a/ than in the /i/ context. The performance of the hearing-impaired listeners was significantly poorer than the performance of the normal-hearing listeners only for the higher-frequency features of frication and sibilance. The lower-frequency features of voicing and sonorance were reflected in the confusion matrices of hearing-impaired listeners at presentation levels of 10 and 20 dB; only at 35 to 65 dB were higher-frequency features transmitted in the confusion matrices of this group.

Adult↗

PubMed1978

Effect of contralateral noise on the middle components of the averaged electroencephalic response.

Middle-component AERs were obtained from normal-hearing adults to 1000-Hz tone pips at 20 and 40 dB SL and at silent control. A continuous noise at 20, 40, and 80 dB SL and at silent control was presented to the contralateral ear. When the tone pips were at 20 or 40 dB SL, five peaks were identified visually in waveforms constructed by digitally adding AERs across subject and replication. Peak latencies determined from the composite waveforms for each signal-masker condition were used as time points to measure point-to-point amplitudes in individual AERs. The masker at 20 or 40 dB SL did not alter or degrade the AER produced by the tone pip. It was concluded that clinical masking may be used in EEA when the middle components of the AER are employed as a response index.

Adolescent↗

PubMed1977

The acoustic reflex and temporary threshold shift: temporal characteristics.

One ear of each of seven normal-hearing subjects was exposed to a continuous 1000-Hz tone at 110 dB SPL for three minutes. During exposure, a broad-band noise at 100 dB SPL was presented to the contralateral ear. The noise was either continuous or pulsed. Four pulsed conditions employed repetition periods of 360, 180, 90, or 9 msec with a 50% duty cycle. A control condition in which no noise was presented was also included. Temporary threshold shift was measured at selected postexposure times at the frequency one-half octave above the exposure frequency. TTS2 was greatest for the control condition and least for the 360- and 180-msec conditions. Results are discussed in relation to the dynamics of the acoustic reflex, particularly reflex relaxation, reflex adaptation, and reflex temporal summation.

Acoustic Stimulation↗