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Biomedical subjects

M K Wynne

Publications and source records attributed to M K Wynne.

13 recordsLinked to original sources
PubMed2001

Objective tinnitus in children.

OBJECTIVE: To discuss the various symptoms and causes of objective tinnitus in children. STUDY DESIGN: Retrospective case review. PATIENTS: Five children who had audible signals emanating from their ears caused by audible spontaneous otoacoustic emissions, palatal myoclonus, arteriovenous malformation, and acoustic trauma. MAIN OUTCOME MEASURE: The tinnitus reported by the patients was linked to acoustic signals that could be measured objectively or heard by the examiner. RESULTS: Four of the five children had essentially normal hearing. The one child who demonstrated a hearing loss audiometrically was thought to have normal hearing sensitivity, but his intense roaring objective tinnitus appeared to mask his low-frequency thresholds. All five patients had measurable acoustic signals in the ear canal that matched the patients' descriptions of their tinnitus. CONCLUSION: The cases illustrate how the objective tinnitus was diagnosed and measured, how a treatment algorithm was applied, and the expected results of treatment. In addition, the cases provide support for the use of psychologic counseling throughout the examination and treatment of objective tinnitus in children.

Adolescent↗
PubMed1999

Measurements of loudness growth in 1/2-octave bands for children and adults with normal hearing.

The loudness growth in 1/2-octave bands (LGOB) procedure has been shown previously to provide valid estimates of loudness growth for adults with normal hearing and those with hearing loss (Allen, Hall, & Jeng, 1990), and it has been widely incorporated into fitting strategies for adult hearing aid users by a hearing aid manufacturer. Here, we applied a simple modification of LGOB to children and adults with normal hearing and then compared the loudness growth functions (as obtained from end-point data) between the two age groups. In addition, reliability data obtained within a single session and between test sessions were compared between the two groups. Large differences were observed in the means between the two groups for the lower boundary values, the upper boundary values, and the range between boundaries both within and across all frequencies. The data obtained from children also had greater variance than the adult data. In addition, there was more variability in the data across test sessions for children. Many test-retest differences for children exceeded 10 dB. Adult test-retest differences were generally less than 10 dB. Although the LGOB with the modifications used in this study may be used to measure loudness growth in children, its poor reliability with this age group may limit its clinical use for children with hearing loss. Additional work is needed to explore whether loudness growth measures can be adapted successfully to children and whether these measures contribute worthwhile information for fitting hearing aids to children.

Adult↗
PubMed1999

Zenker's diverticulum: analysis of surgical complications from diverticulectomy and cricopharyngeal myotomy.

OBJECTIVE: To identify risk factors for postoperative complications in patients undergoing diverticulectomy and cricopharyngeal (CP) myotomy for Zenker's diverticulum. STUDY DESIGN: Retrospective. MATERIALS AND METHODS: A chart review was conducted of all patients with a Zenker's diverticulum who were treated with diverticulectomy and cricopharyngeal myotomy at three tertiary care centers in central Indiana between 1988 and 1998. RESULTS: Of the 24 patients identified, 9 developed postoperative complications (2 medical and 7 surgical). Statistical analysis of multiple potential risk factors revealed that only diverticulum size greater than 10 cm2 at surgery placed the patient at increased risk for postoperative surgical complications. To our knowledge, this is the first report that has specifically addressed diverticulum size as an independent risk factor for postoperative surgical complications following diverticulectomy and CP myotomy. CONCLUSIONS: Given our findings, we recommend considering diverticulopexy rather than diverticulectomy in a patient with a Zenker's diverticulum greater than 10 cm2 in size if a cervical approach is the selected treatment.

Aged↗
PubMed1999

Field trial evaluations of a switched directional/omnidirectional in-the-ear hearing instrument.

The use of directional microphones is one of the few methods available for hearing aids to increase the signal-to-noise ratio. The smaller microphones available with today's technology have increased the viability of their application for in-the-ear (ITE) hearing aids. This study evaluated an ITE hearing aid containing two nondirectional microphones that provides wearer-selectable omnidirectional/directional operating modes. Ten sensorineural hearing-impaired patients were fitted binaurally. During the first trial period, the low-frequency gain decrease produced by the directional mode was not compensated for. The frequency responses were matched during the second trial period. For both trial periods, Hearing in Noise Test results using two uncorrelated noise sources indicated significant speech recognition improvements for the directional mode relative to the omnidirectional mode. Responses on Abbreviated Profile of Hearing Aid Benefit questionnaires, paired-comparison judgments, and interview data revealed that most subjects preferred the directional mode in noisier environments, but many also preferred the omnidirectional mode in quiet listening.

Aged↗
PubMed1997

Wound complications associated with brachytherapy for primary or salvage treatment of head and neck cancer.

Brachytherapy can be employed in the primary or salvage treatment of head and neck cancer. The advantage of brachytherapy is the stereotactic limitation of radiation exposure to noninvolved tissues. Wound complications associated with brachytherapy have been discussed only sporadically in the literature. This retrospective study examines 28 patients, 20 for initial treatment and eight for salvage, with varying site and stage head and neck cancer treated with brachytherapy in addition to external beam radiation therapy and/or surgery. The overall complication rate was 50% (14/28), with infection and minor flap breakdown being the most common problems. Tumor site in the primary treatment group was the only significant factor in wound complications. In the salvage group complications were minor and primarily related to flap coverage of brachytherapy catheters.

Adolescent↗
PubMed1997

Differences in performance between Oticon MultiFocus Compact and ReSound BT2-E hearing aids.

Differences in performance were evaluated between binaural fittings of the Oticon MultiFocus (MF) and ReSound BT2-E on 25 hearing-impaired subjects across two sites. Subjects were initially fit using each manufacturer's algorithm and adjustments were made at 1 week based on subjects' responses to diary questions. Performance was assessed after a 4- to 6-week trial period with each hearing aid set using the Speech Perception in Noise (SPIN) test administered at 50, 65, and 80 dB SPL, the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire, loudness judgments of female connected discourse at 65 and 80 dB SPL, and an overall preference selection. The MF yielded significantly better SPIN scores at 50 and 65 dB SPL, while the BT2-E yielded a significantly better score at 80 dB SPL. No statistically significant differences were found in the APHAB benefit scores between the hearing aid sets, but both sets were significantly better than the subjects' own hearing aids on three of the four subscales. The MF produced slightly higher mean loudness judgments at both input levels than the BT2-E. Finally, 12 subjects preferred the BT2-E, 10 subjects preferred the MF, and three subjects stated no preference. The results are discussed in terms of audiogram effects on preference and effects of differences in signal processing approaches between the devices.

Audiometry↗
PubMed1994

Prediction of 8-hour noise dose from brief duration samples.

The purpose of this study was to determine whether brief duration samples of noise dose measurements could predict the noise exposure levels of employees as measured by 8-hour dosimetry. Sampled noise dose measurements were obtained for 1, 5, 10, 15, and 20 minutes and 8 hours for four workers at each of four industrial sites. Statistical analyses indicated no significant differences or interactions among trials and sample durations. A simple linear prediction model provided the best fit for the four shortest of the five abbreviated sample durations, whereas an exponential regression model provided the best predictions using the 20-minute sample duration. The high variance and low correlations across all measures permitted only poor predictions from these abbreviated sample data. Based on these results, sampled noise measurements of short duration (1 to 20 minutes) do not appear to be a valid means for predicting the amount of noise exposure during an 8-hour shift.

Acoustic Stimulation↗
PubMed1987

Auditory brain stem responses from human adults and infants: wave V tuning curves.

Decrement in ABR wave V amplitude was measured in the presence of simultaneous tonal maskers. Probe stimuli were 1.0, 4.0, and 8.0-kHz third-octave-filtered clicks. Adults and 3-month-old infants served as subjects. The resultant amplitude-decrement functions for each tonal masker were fit with regression lines. The sound pressure level (SPL) required to reduce wave V to 50% of the unmasked probe amplitude was plotted for each masker to develop tuning curves. The tuning curves were quantified by calculations of tip-to-tail difference, Q 10, and SPL at maximum masker frequency (MMF). Tuning curves for adult and infant subjects were similar for the 1.0-kHz probe. For the high-frequency probes (4.0 and 8.0 kHz), smaller tip-to-tail differences and lower Q 10 values were observed for the infant subjects. Ranges of MMF level were similar across adult and infant subjects. For the 8.0-kHz probe, tuning curves from infant subjects consistently showed maximum masker frequencies which were lower than the probe.

Acoustics↗
PubMed1986

Auditory brain stem responses from human adults and infants: restriction of frequency contribution by notched-noise masking.

The frequency contribution to the click-evoked ABR wave V was examined in adults and 3-month-old infants through the use of notch-filtered broadband noise. Notch center frequencies were set at 1.0, 4.0, and 8.0 kHz. Responses were obtained at 20, 40, and 60 dBnHL during the simultaneous presentation of each notched-noise masker as well as in an unmasked condition. The ABR wave V was analyzed for absolute latency and amplitude, as well as latency and amplitude changes resulting from the introduction of masking. Analyses showed wave V latency and amplitude values to be similar for adults and infants within the 1.0-kHz notch. Differences between adult and infant groups were observed as the notch was shifted to the high frequencies. Further, latency and amplitude shifts resulting from the introduction of masking noise produced differential effects on infant responses when compared to adults.

Adult↗
PubMed1982

Central auditory function in fluent and disfluent normal speakers.

The Synthetic Sentence Identification - Ipsilateral Competing Message (SSI-ICM) test at a -20-dB message-to-competition ratio was used to investigate central auditory function of fluent and disfluent, normally speaking, male college students. The disfluent group consisted of 10 subjects who demonstrated part-word repetitions while speaking extemporaneously. The matched fluent group of 10 subjects had extemporaneous speech containing no part-word repetitions and with speaking times matched to those of the disfluent group. All subjects had intact peripheral hearing skills and no known history of stuttering. As hypothesized, the disfluent normal speakers had lower scores on the SSI-ICM test than did the fluent normal speakers. It was suggested that a central auditory variable may be one of the factors contributing to the production of disfluent speech at the level of syllable production. It was further suggested that this relationship is not one limited to the clinical or stuttering population as suggested by the design of previous research.

Adolescent↗
PubMedDate not supplied

External and middle ear trauma resulting from ear impressions.

When taking an impression of the external ear canal and ear, the audiologist is engaged in an invasive procedure whereby a foreign body is first placed into the ear canal and then removed. There is always an element of risk for significant medical problems when a clinician is performing an invasive procedure. Although some minor patient discomfort and, at times, some slight trauma to the ear canal occur when taking ear impressions, the incidence of significant trauma to the external or middle ear appears to be low. The purpose of this report is to provide some illustrative cases of significant external and middle ear trauma as a result of taking impressions of the external ear. Audiologists are advised to develop and implement an appropriate risk management program for taking ear impressions to reduce the potential risks associated with this procedure to their patients and to their practices.

Aged↗