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Biomedical subjects

D Noffsinger

Publications and source records attributed to D Noffsinger.

At least 19 recordsLinked to original sources
PubMed2000

Efficacy of 3 commonly used hearing aid circuits: A crossover trial. NIDCD/VA Hearing Aid Clinical Trial Group.

CONTEXT: Numerous studies have demonstrated that hearing aids provide significant benefit for a wide range of sensorineural hearing loss, but no carefully controlled, multicenter clinical trials comparing hearing aid efficacy have been conducted. OBJECTIVE: To compare the benefits provided to patients with sensorineural hearing loss by 3 commonly used hearing aid circuits. DESIGN: Double-blind, 3-period, 3-treatment crossover trial conducted from May 1996 to February 1998. SETTING: Eight audiology laboratories at Department of Veterans Affairs medical centers across the United States. PATIENTS: A sample of 360 patients with bilateral sensorineural hearing loss (mean age, 67.2 years; 57% male; 78.6% white). INTERVENTION: Patients were randomly assigned to 1 of 6 sequences of linear peak clipper (PC), compression limiter (CL), and wide dynamic range compressor (WDRC) hearing aid circuits. All patients wore each of the 3 hearing aids, which were installed in identical casements, for 3 months. MAIN OUTCOME MEASURES: Results of tests of speech recognition, sound quality, and subjective hearing aid benefit, administered at baseline and after each 3-month intervention with and without a hearing aid. At the end of the experiment, patients ranked the 3 hearing aid circuits. RESULTS: Each circuit markedly improved speech recognition, with greater improvement observed for soft and conversationally loud speech (all 52-dB and 62-dB conditions, P</=.001). All 3 circuits significantly reduced the frequency of problems encountered in verbal communication. Some test results suggested that CL and WDRC circuits provided a significantly better listening experience than PC circuits in word recognition (P =.002), loudness (P =.003), overall liking (P =.001), aversiveness of environmental sounds (P =.02), and distortion (P =.02). In the rank-order ratings, patients preferred the CL hearing aid circuits more frequently (41.6%) than the WDRC (29.8%) and the PC (28.6%) (P =.001 for CL vs both WDRC and PC). CONCLUSIONS: Each circuit provided significant benefit in quiet and noisy listening situations. The CL and WDRC circuits appeared to provide superior benefits compared with the PC, although the differences between them were much less than the differences between the aided vs unaided conditions. JAMA. 2000;284:1806-1813.

Adult↗
PubMed1999

An individualized, sensitive frequency range for early detection of ototoxicity.

OBJECTIVE: The aim of this study was to identify auditory frequencies at which serial threshold testing would provide the greatest sensitivity for early detection of ototoxicity. The overall objective is to develop a more time-efficient ototoxicity monitoring protocol. DESIGN: Threshold data were analyzed from 370 hospitalized patients treated with aminoglycoside antibiotics (AMGs) or cisplatin (CDDP) who received serial auditory monitoring before, during, and after treatment at conventional (0.25 to 8 kHz) and high (9 to 20 kHz) frequencies. RESULTS: For patients showing hearing changes due to ototoxicity, a frequency range was identified for its apparent high sensitivity to initial ototoxicity. This sensitive range is identified according to an individual's hearing threshold configuration, and is, therefore, unique for each patient. The range consists of five frequencies, generally separated by 1/6 octave, e.g., 8, 9, 10, 11.2, and 12.5 kHz. To determine frequencies and combinations of frequencies that were most often involved in ototoxicity detection, threshold data in the sensitive range were analyzed in detail. This analysis suggests that patients receiving treatment with AMG or CDDP can be monitored for hearing thresholds at only five frequencies, resulting in an 84% detection rate for AMG and 94% for CDDP compared with monitoring at all conventional and high frequencies. CONCLUSIONS: This comprehensive analysis supports earlier observations that a sensitive, limited frequency range exists in which serial threshold monitoring will provide early warning of ototoxicity before effects in the speech frequency range. This finding is now being evaluated in a prospective investigation.

Aminoglycosides↗
PubMed1996

Dichotic listening to speech: VA-CD data from elderly subjects.

The Department of Veterans Affairs (VA) compact disc (VA-CD) Tonal and Speech Materials for Auditory Perceptual Assessment, Disc 1.0 contains three dichotic speech tests. Two of them, namely, dichotic digits and dichotic synthetic sentences, are tasks that are easily and accurately performed by young normal listeners. The third test, dichotic nonsense syllables, is a more difficult task for normal listeners to perform well. Few data have been gathered from use of the VA-CD with subjects other than young adults with normal hearing sensitivity. This account is about 19 elderly patients with hearing loss in a VA long-term care facility and how they performed on the trio of dichotic tasks on the disc. The digits, sentences, and syllables were presented at 80 dB SPL in a dichotic format requiring two responses to each trial. Trials using syllables were also done at 90 dB SPL to quantify the effects of hearing loss. Digits were recognized better than sentences; both were recognized better than syllables, and this was true for both ears. Compared to results from young listeners, correct responsiveness for older people was most reduced on the syllable task, but performance on dichotic sentences was also reduced. The results corroborate previous reports that suggest that many aging auditory systems do not process dichotic nonsense syllables as well as younger ones. The results also suggest that the dichotic procedures on the VA-CD provide a useful continuum of difficulty for the clinician and investigator.

Aged↗
PubMed1994

High-frequency audiometric monitoring strategies for early detection of ototoxicity.

Therapeutic drugs such as the aminoglycoside antibiotics (AMG) and the chemotherapy agent cisplatin (CDDP) are known to cause irreversible hearing loss, typically affecting highest frequency hearing first with progression of loss to the lower frequency regions. Conventional (0.25-8 kHz) and high-frequency (9-20 kHz) serial hearing threshold monitoring was done in 123 hospitalized patients (222 ears) administered AMG or CDDP. Of ears showing a decrease in sensitivity corresponding with treatment, 62.5% demonstrated initial hearing loss solely in the high-frequency range, 13.5% first showed loss only in the conventional-frequency range, and 24.0% showed loss in both frequency ranges concurrently. Thus, if only high frequencies had been monitored, early change in auditory sensitivity would have been detected in 86.5% of these patients. Further analysis revealed a range of five frequencies, specific to each individual's hearing threshold configuration, in which initial ototoxicity appeared most likely to be detected. Testing only these five frequencies would have identified 89.2% of ears that showed change. The results of this study confirm the need to serially monitor auditory thresholds, especially in the high-frequency range, of patients receiving ototoxic drugs. A shortened five-frequency monitoring protocol is presented and suggested for use with patients unable to tolerate lengthy audiometric testing procedures.

Aminoglycosides↗
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

Dichotic listening to musical chords: background and preliminary data.

One test of dichotic listening utilizing nonverbal stimuli is included on the VA-CD Tonal and Speech Materials for Auditory Perceptual Assessment, Disc 1.0. It is a test using three tone complexes that meet the definition of musical chords. The dichotic chords were included as a complement to the three dichotic speech procedures on the VA disc because musical chords may depend on right hemisphere brain function in a manner at least related to the way speech depends on left hemisphere organization/activity. Normative data were obtained from 120 normal-hearing listeners at nine testing centers in the United States. The three tone chords were presented dichotically under two onset time conditions, simultaneous and 90-msec onset time stagger, and three presentation levels, 70, 80, and 90 dB SPL. In general, subjects could identify the dichotically presented chords about 60 percent of the time in each ear. In addition, onset time relationships and presentation levels did not greatly affect accuracy. Overall, subject performance was similar to that noted by others and at levels that should allow lesion effects to be sought.

Auditory Perception↗
PubMed1994

Dichotic listening to speech: background and preliminary data for digits, sentences, and nonsense syllables.

Three tests of dichotic listening utilizing speech signals as stimuli are included on the VA-CD Tonal and Speech Materials for Auditory Perceptual Assessment, Disc 1.0. They include a dichotic monosyllabic digits task, a dichotic synthetic sentences task, and a dichotic nonsense syllable (CV) task. Since the materials were specially recorded or created and recorded for use on the VA-CD, normative data were collected at nine universities/medical centers in the United States involving 120 young listeners. Data revealed that these listeners had little difficulty correctly identifying digits or synthetic sentences when they were presented at 50-70 dB HL in a dichotic format requiring two responses to each trial. At the same presentation levels and under two onset-time conditions (0- and 90-msec onset stagger), correct responsiveness was less frequent when the stimuli were dichotic CVs. However, scores fell in ranges consistent with previous studies and useful for seeking lesion effects. Although careful definition of stimuli, standardization of materials, and the relative stability offered by audio compact disc technology were prime reasons for making the VA-CD, another goal was to offer the clinician-researcher a range of difficulty among the procedures on the disc. Data from the normative trials using dichotic speech signals suggest that the goal has been accomplished.

Compact Disks↗
PubMed1985

Identification of synthetic, voiced stop-consonants by hearing-impaired listeners.

The identification of synthetic, voiced stop consonants changing in place of articulation was investigated in 26 normal-hearing listeners and 16 hearing-impaired listeners who reported difficulties in speech understanding, but attained high speech discrimination scores on standard test materials. Two place continua (each containing 13 stimuli changing from /ba/ to /da/ and /ga/) were employed: a continuum in which place was cued by an initial noise burst and formant transitions, and a continuum in which place was cued by formant transitions alone. All normal listeners exhibited categorical and highly consistent identification for both stimulus continua. For the hearing-impaired listeners, identification was somewhat less consistent for the burst-and-transition stimuli, and much poorer for the transition-only stimuli. Similar differences were observed when comparing the responses of 4 subjects with a unilateral hearing loss when the stimuli were presented to their normal and impaired ears, and 2 subjects with a unilateral, sudden-onset hearing loss with recovered pure-tone sensitivity.

Adolescent↗
PubMed1983

Effects of stimulus repetition rate and frequency on the auditory brainstem response in normal cochlear-impaired, and VIII nerve/brainstem-impaired subjects.

The effects of signal repetition rate and frequency on the auditory brainstem responses of normal listeners, of persons with cochlear lesions, and of persons with VIII nerve/brainstem lesions were evaluated. The normal group exhibited more waves I and II than did the cochlear and VIII/brainstem groups. The normal and cochlear groups exhibited more waves III and V than did the VIII nerve/brainstem group. The latency of wave I was not different among groups, whereas wave V was significantly later in the VIII nerve/brainstem group than in the other groups. Waves I, III, and V were later for 50/s than for 10/s. Waves I and III displayed shorter latencies for 4000 Hz than for 2000 Hz, whereas wave V displayed similar latencies for the two stimuli. In conclusion, cochlear pathology (less than or equal to 65 dB HL) does not prolong the latencies of waves I and V. A dual mechanism is discussed to explain the rate-dependent latency shift of wave V.

Adult↗
PubMed1982

Clinical applications of selected binaural effects.

Examination was made of the behaviors exhibited on selected binaural tasks by 556 persons with diagnosed peripheral hearing loss or central nervous system damage. The tasks used included loudness balancing (LB), intracranial midline imaging (MI), masking level differences (MLD), and binaural beats (BB). The methods used were chosen for their clinical utility. Loudness balancing and midline imaging were of the most diagnostic value when hearing loss was present. Masking level differences were best at detecting pathology which did not produce hearing loss. None of the techniques were sensitive to cortical damage.

Adolescent↗
PubMed1982

Auditory brainstem responses and masking level differences from persons with brainstem lesion.

Twenty subjects with abnormal auditory brainstem responses (ABR) and diagnosed brainstem lesion or disease were studied. Normal listeners were used as controls. The objective of the project was to examine the relationship of the particular ABR patterns exhibited by these subjects to the binaural masking level differences (MLD) and transbrainstem acoustic reflex (AR) patterns yielded by the same subjects. Patients whose ABR abnormalities commenced with brainstem potentials I, II, or III had small or no MLD and absent or abnormal AR. Patients whose ABR abnormalities commenced with brainstem potentials IV or V yielded normal MLD and AR behavior. Most important, these findings suggest that MLD size is influenced by activity which also contributes importantly to the development of the early auditory brainstem potentials.

Adult↗
PubMed1982

Brain stem auditory evoked potentials: applications in clinical audiology.

The brain stem auditory evoked potentials (BAEP) or, more appropriately, the auditory brain stem response (ABR) is a series of 5-7, vertex-positive, time-locked electric events. They are usually aroused by a brief, rapid onset, high intensity acoustic click or tonal pip. The vertex positive nature of the events is dictated by the placement of surface electrodes, usually featuring an active electrode on the vertex, a referent electrode on the mastoid or earlobe ipsilateral to the signal source, and a ground electrode on the forehead or other neutral tissue. The size of the ABR is sufficiently small, often fractions of a microvolt, to require the use of many signal presentations (1000-2000 stimuli) and digital averaging of the resulting electrical activity for the stimulus time-locked potentials to be elicited from other physiologic "noise." Since the auditory brain stem potentials are known to be elicitable near a subject's behavioral threshold for the stimulus used, and since the various potentials are thought to originate from different points in the brain stem, they have proved useful in hearing evaluations of human beings for two purposes: a) they are useful as a means of measuring hearing sensitivity from patients who cannot or will not give accurate voluntary responses; and b) they are useful as a diagnostic tool for determining the probable cause of an auditory disorder.

Brain Stem↗
PubMed1980

Aging, memory, and the cholinergic system: a study of dichotic listening.

Impairment of cholinergic neural function has been proposed as a cause of memory and cognitive (M/C) disorders of the aged since with cholinergic blockade young subjects show the M/C pattern of the elderly. To validate this hypothesis, we compared the performance of young normal subjects, young scopolamine-treated subjects, and aged subjects, using a different type of behavioral task, a dichotic listening test, which primarily measures neural channel capacity. With simultaneous dichotic presentation, undrugged young subjects reported both messages correctly in 35% of trials. Aged subjects scored double-correct responses in only 19% of trials, a highly significant difference (p less than 0.001). Following treatment with 1.0 mg scopolamine, young subjects also scored double correct responses in only 19% of trials, a highly significant reduction from their undrugged performance (p less than 0.01), but virtually the same as that of normal aged subjects. Similar findings were obtained with a staggered dichotic presentation. These results extend the observation that cholinergic blockade in young subjects reproduces the pattern of M/C decline of the aged; thus providing further for the hypothesis that this decline may result from impaired function in cholinergic neurons. The neurobiologic implications of cholinergic impairment are discussed.

Adult↗
PubMed1976

Eustachian tube function in children.

Eustachian tube function of children with bilateral serous otitis media was studied in 14 ears following myringotomy and pressure equalizing tube insertion. Cases with non-Eustachian tube pathology potentially contributing to Eustachian tube dysfunction were excluded from the study. Eustachian tube function was evaluated utilizing an impedance audiometer to document neutralization of positive and negative middle ear pressures. All cases showed persistent tubal dysfunction for up to six months. Partial incomplete neutralization of positive pressure occurred in 64 per cent, but in no case could negative pressure be partially neutralized even when "locking" was relieved with valsalva. Continuous ventilation of the middle ear for up to six months did not allow a return to normal Eustachian tube function. This is extremely effective palliation, and should be recognized as such.

Child↗
PubMed1975

Bekesy test results in patients with eighth-nerve lesions. Forward reverse- and fixed-frequency tracings.

Sweep-frequency Bekesy tracings, both forward (low to high frequency) and reverse (high to low frequency), as well as fixed-frequency tracings, were obtained from 18 patients who had eighth-nerve tumors (subsequently confirmed surgically). In general, reverse-sweep frequency tracings revealed greater adaptation for continuous tone stimuli than did forward-sweep frequency tracings. However, if a search for excess adaptation (greater than 20 dB) is the sole purpose for administering Bekesy audiometry to a given patient, then fixed-frequency tracings yield adequate differential information.

Adaptation, Physiological↗
PubMed1975

Acoustic reflex and reflex decay. Occurrence in patients with cochlear and eighth nerve lesions.

Acoustic reflex and reflex decay tests were administered to 50 normal ears, 50 ears with hearing loss due to noise trauma, 50 ears that had Meniere disease, and 28 ears that had involvement of the eighth nerve. In one normal ear, ten noise trauma ears, 11 Meniere disease ears, and 24 eighth nerve lesion ears to reflexes or reflex decay that were suggestive or retrocochlear lesions were observed. Acoustic reflex and reflex decay results are also compared to tone decay results for these patients.

Acoustic Stimulation↗