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Biomedical subjects

A Stuart

Publications and source records attributed to A Stuart.

At least 19 recordsLinked to original sources
PubMed2001

Producing the vowel/a/ prior to speaking inhibits stuttering in adults in the English language.

This study investigated the effects of producing and listening to the vowel /a/ on the frequency of overt stuttering moments in eight people who stuttered. Stuttering frequency counts were made for the speech produced in the control condition, and after each of these four experimental conditions: (a) producing a vowel /a/ for 4 s; (b) producing a vowel /a/ for 4 s and waiting for 4 s; (c) listening to a recording of the vowel /a/ for 4 s; and (d) listening to a recording of the vowel /a/ for 4 s and waiting for 4 s. A significant reduction in the stuttering frequency was only observed following production of the vowel /a/ without a 4 s delay (P=0.02), suggesting that the vowel production prior to speech, serves as a temporary fluency enhancer. Its similarity to the occurrence of overt stuttering moments (e.g. discrete part-word repetitions and prolongation's) and its relationship to the fundamental nature of the pathology are discussed.

Adolescent↗
PubMed2001

Effects of age, gender, bolus volume, and trial on swallowing apnea duration and swallow/respiratory phase relationships of normal adults.

The effects of age, gender, bolus volume, and trial on swallowing apnea duration (SAD) and swallow/respiratory phase relationships were examined. Sixty adults, composed of ten males and ten females in each of three age groups (i.e., 20-39, 40-59, and 60-83 years), participated. SAD was assessed via nasal airflow during saliva swallows and 10-, 15-, 20-, 25-mL bolus volumes across three trials. Results revealed SAD is consistent across trial (p > 0.05). Significant main effects of age, gender, and bolus volume were found (p < 0.05), i.e., elderly adults had longer SAD than young and middle-aged adults; women had longer SAD than men; and SAD increased as bolus volume increased. With respect to saliva swallows, a significant interaction of age by gender was found (p < 0.05), i.e., males exhibited a decrease in SAD with increasing age while females exhibited an increase in SAD with increasing age. Concerning swallow/respiratory phase relationships, the pattern of exhale-swallow-exhale was evident during 62% of participants' swallows. Furthermore, age, gender, or bolus volume did not predict the pattern of exhale-swallow-exhale (p > 0.05).

Age Factors↗
PubMed2001

Effect of age, gender, and repeated measures on intraoral air pressure in normal adults.

The effect of age, gender, and repeated measures on intraoral air pressure (P0) was examined. Sixty adults comprised of 10 males and 10 females in each of three age groups (i.e., 20-39, 40-59, and 60-83 years) participated. P0 was assessed during voiceless stop plosive /p/ productions in repeated vowel/consonant syllables. The three medial plosives of a seven-syllable train were averaged to comprise a token. Five tokens were obtained and averaged for each of three trials. Thus each participant contributed 105 syllables and a subsequent three P0s for analyses. There was no statistically significant difference in P0 as a function of age or gender (P > 0.05). These findings support the conception that P0 remains stable throughout adulthood and is not dependent on gender. Differences in repeated measures of P0 attained statistical significance (P = 0.03), however the mean differences between trials (0.23 cm H20) were negligible and deemed to be clinically insignificant. Thus, across a short sampling session, P0 is a relatively stable measurement and does not change as a function of age or gender.

Adult↗
PubMed2001

Transmission loss of sound into incubators: implications for voice perception by infants.

OBJECTIVE: To assess the transmission of sound into incubators as a function of talker position (i.e., standing or sitting), incubator port position (i.e., opened or closed), and center frequency (i.e., 125 to 10,000 Hz in one-third octave steps). The second objective was to estimate the audibility of the human voice inside the incubator. STUDY DESIGN: L(eq) measures of signal transmission loss and motor noise were obtained from two incubators. RESULTS: In general, signal transmission loss was greater for the standing-talker position, with front portholes closed, and for high-frequency spectra. Motor noise was greater with both front portholes closed and for lower-frequency spectra. The greatest signal delivery to an infant would be obtained when the speaker is sitting using a raised vocal effort while the incubator ports are opened. CONCLUSION: Measured signal transmission loss and motor noise characteristics of two incubators suggest that only mid-frequency speech spectra would be audible to infants and only at a speech-to-noise ratio of approximately 5 to 10 dB with a raised vocal effort.

Acoustics↗
PubMed2001

Effects of exercise and noise on auditory thresholds and distortion-product otoacoustic emissions.

Differences in auditory thresholds and distortion-product otoacoustic emission (DPOAE) levels were investigated as a function of gender, ear, frequency, and experimental condition: quiet sedentary activity, exercise, noise, and exercise and noise combined. In general, participants displayed significant elevations in auditory thresholds of approximately 6 to 13 dB following the two conditions employing noise exposure. There were no significant differences in either auditory threshold differences before and following the quiet and exercise conditions or between the noise-alone and combined exercise and noise conditions. Participants also displayed significant reductions in DPOAE levels of approximately 6 to 7 dB following the two conditions employing noise exposure. The findings also showed no gender or ear effects on auditory threshold or DPOAE level differences. Further, there was no evidence of a synergistic combination of exercise and noise on auditory function as revealed by changes in hearing threshold or DPOAE levels.

Adult↗
PubMed2001

Interactive effects of low-pass filtering and masking noise on word recognition.

A word recognition in noise paradigm was employed to examine temporal resolution in individuals with simulated hearing loss. Word recognition scores were obtained for low-pass filtered speech (i.e., cutoff frequencies of 1000,1250, and 1500 Hz) presented in continuous and interrupted noise at signal-to-noise ratios (SNRs) of -10, 0, and 10 dB. Performance improved with increasing SNR and low-pass frequency filter settings. Generally, word recognition performance was better in the interrupted noise condition than the continuous noise condition. This effect was greatest in the -10 dB SNR condition. Since the continuous/interrupted performance difference steadily declined as a function of low-pass filter cutoff frequency, these findings suggest that one factor leading to poorer speech recognition in individuals with high-frequency hearing impairment may be their dependence on low-frequency hearing channels that are inherently poorer than high-frequency channels for temporal resolution.

Adult↗
PubMed2000

Stutter-free and stutter-filled speech signals and their role in stuttering amelioration for English speaking adults.

This study examined the power of an exogenously generated stuttered speech signal on stuttering frequency when compared to an exogenously generated normal speech signal. In addition, we examined the specific components of the second speech signal, which might be responsible for the inducement of fluency in people who stutter. Eight males and two females who stuttered participated in this study. Experiment I involved meaningful speech: normal continuous speech, normal interrupted speech, stuttered continuous speech, and stuttered interrupted speech, whereas Experiment II involved vowels and consonants: /a/, /a-i-u/, /s/, /s-sh-f/. The results indicated that stuttered and normal speech signals were equally effective in reducing stuttering frequency. Further, the vowels were more powerful than consonants in inducing fluency for people who stutter. It is suggested that acoustic manifestations of stuttering, rather than a problem, may be a natural compensatory mechanism to bypass or inhibit the 'involuntary block' at the neural level.

Adult↗
PubMed2000

Inducement of fluent speech in persons who stutter via visual choral speech.

A novel phenomenon of fluency enhancement via visual gestures of speech in the absence of traditional auditory feedback is reported herein. The effect on visual choral speech on stuttering frequency was investigated. Ten participants who stuttered recited memorized text aloud under two conditions. In a visual choral speech (VCS) condition participants were instructed to focus their gaze on the face, lips and jaw of a research assistant who 'silently mouthed' the text in unison. In a control condition, participants recited memorized text to the research assistant who sat motionless. A statistically significant (P=0.0025) reduction of approximately 80% in stuttering frequency was observed in the VCS condition. As visual linguistic cues are sufficient to activate the auditory cortex, one may speculate that VCS induces fluency in a similar yet undetermined manner as altered auditory feedback does.

Adult↗
PubMed2000

The effect of an educational patient compliance program on serum phosphate levels in patients receiving hemodialysis.

OBJECTIVE: This study sought to determine the effectiveness of a recently developed educational patient compliance program (A Taste for Life [1995]; Abbott Laboratories, Abbott Park, IL) on improving serum phosphate levels in patients receiving hemodialysis. DESIGN: An ABA time series design was used. PARTICIPANTS/SETTING: Eighty-one patients receiving hemodialysis participated. The experimental group consisted of 50 participants (mean [M] = 57.9 years of age; 92% African-American; 62% female) from a private freestanding dialysis unit (Kinston, NC). The control group consisted of 31 control participants (M = 58.2 years of age; 90% African-American; 48% female) from a separate private freestanding dialysis unit (Greenville, NC). INTERVENTION: The experimental group took part in the educational patient compliance program directed at dietary and medical regimes. The program used educational materials, interactive educational modules, motivational posters, creative games and puzzles, videos, and an in-center achievement contest. The control group did not partake in the program, but received individual ongoing monthly therapy that involved nutrition counseling consistent with the National Renal Diet (American Dietetic Association, 1993) and instruction regarding use of phosphate binders. MAIN OUTCOME MEASURE: Serum phosphate levels were monitored monthly for 1 year (ie, 3, 3, and 6 months during pretreatment, treatment, and posttreatment, respectively). RESULTS: No statistically significant differences were found in serum phosphate levels between the two groups (P >.05). There was, however, a significant difference across time within groups. Mean serum phosphate levels significantly declined during the treatment period and further during the posttreatment period relative to the pretreatment baseline (P <.05). Results were not compared with a group of patients receiving hemodialysis who received no nutrition counseling. CONCLUSION: The findings suggest that an educational compliance program is equally effective as standard individual ongoing counseling in affecting serum phosphate levels among patients with end-stage renal disease who receive hemodialysis. Results suggest that renal dietitians choose types of intervention within each patient's continuity of care that support individual success.

Adult↗
PubMed2000

An investigation of maternal stress after neonatal hearing screening.

An investigation was undertaken to determine whether mothers whose infants failed a newborn hearing screening (MWIF) had significantly more stress and were consequently at risk for dysfunctional attachment than those mothers whose infants passed a newborn hearing screening (MWIP). The Parenting Stress Index (PSI; Abidin, 1995), a screening and diagnostic assessment questionnaire designed to measure the relative magnitude of stress in a parent-child dyad, was used. Twenty MWIP and 20 MWIF participated. The PSI was administered through a telephone interview approximately 1 month after participants' discharge while their infants were between their fourth and fifth week of life. In the case of MWIF, the interview occurred before their infant's hearing retest. No significant differences in Total Stress, Life Stress, Child Domain, and Parent Domain subscale raw scores of the PSI were found between MWIP and MWIF (p > .05). An examination of the individual PSI profiles of all participants for "high" and "low" normative percentile scores (i.e., percentile scores > or = 90th percentile and percentile scores < or = 0 percentile for the former and latter, respectively) revealed that the incidence of high scale/subscale percentile scores was essentially equivalent between groups. MWIP, however, displayed lower scale/subscale percentile scores. The results of the study suggest that those mothers whose infants receive a refer outcome after a newborn hearing screening demonstrate equivalent stress levels as those mothers whose infants received a pass.

Adult↗
PubMed2000

Evaluation of a direct doctor-patient telephone advice line in general practice.

A general practitioner-staffed direct access telephone advice line was made available for 30 minutes every morning at an inner-London practice to advise patients with urgent problems. Users valued the service, but the impact on surgery consultations was too small for this to be advocated as an alternative to emergency consultations.

Family Practice↗
PubMed1999

The effects of venting on in-the-ear, in-the-canal, and completely-in-the-canal hearing aid shell frequency responses: real-ear measures.

The acoustic effects of 1-, 2-, and 3-mm vents were investigated with in-the-ear, in-the-canal, and completely-in-the-canal hearing aid shells. Real-ear sound pressure level measures were obtained from unvented and vented shells with 12 adults. In general, with increasing vent size, a statistically significant (p < .05) increase in the amount of low-frequency reduction, an upward shift in vent cutoff frequencies, and an upward shift in vent-associated resonances occurred for all hearing aid shell styles. There was no significant change in the slope of the low-frequency reduction across all hearing aid shell styles (p > .05), albeit the frequency response curves were shifted upward in frequency with increasing vent diameters. Only with the in-the-ear and completely-in-the-canal hearing aid shells were statistically significant (p < .05) differences found with the magnitude of vent-associated resonance as a function of vent diameter, and these differences were not consistent across the different styles. These findings suggest that venting may be used effectively to tune low-frequency responses in custom in-the-ear hearing instruments.

Adult↗
PubMed1999

Effects of monitoring condition and frequency-altered feedback on stuttering frequency.

The purpose of the study was to examine stuttering frequency during speaking conditions that are believed to mitigate stuttering frequency both with normal nonaltered auditory feedback (NAF) and a known fluency-enhancing feedback. Specifically, stuttering frequency was examined as a function of three monitoring conditions under NAF and frequency-altered feedback (FAF): no monitoring (i.e., speaking alone, in the absence of audio and visual recording), audiovisual monitoring (i.e., speaking alone with audiovisual recording), and audiovisual monitoring with observers (i.e., speaking with audiovisual recording in the presence of two observers). Seven adults and one adolescent who stutter served as participants. Stuttering frequency was differentially affected across monitoring conditions under each auditory feedback condition (p = .027). Post hoc analyses revealed no significant difference in stuttering frequency between the two conditions in the absence of the observers (i.e., no monitoring vs. audiovisual monitoring) under NAF (p = .45). There was, however, a significant difference in stuttering frequency for the no-monitoring and audiovisual-monitoring conditions relative to the audiovisual-monitoring-with-observers condition (p = .0002). There was no statistically significant difference in stuttering frequency across monitoring conditions under FAF (p > .05). The findings are consistent with the notion that during NAF stuttering frequency varies as a function of hierarchical socio-environmental conditions in which inanimate monitoring conditions constitute one entity. Such a relationship does not exist during FAF.

Adult↗
PubMed1998

Effect of extended exposure to frequency-altered feedback on stuttering during reading and monologue.

An ABA time series design was used to examine the effect of extended, continuous exposure to frequency-altered auditory feedback (FAF) during an oral reading and monologue task on stuttering frequency and speech rate. Twelve adults who stutter participated. A statistically significant decrease in number of stuttering events, an increase in number of syllables produced, and a decrease in percent stuttering was observed during the experimental segment relative to baseline segments for the oral reading task. In the monologue task, there were no statistically significant differences for the number of stuttering events, number of syllables produced, or percent stuttering between the experimental and baseline segments. Varying individual patterns of response to FAF were evident during the experimental segment of the reading task: a large consistent reduction in stuttering, an initial reduction followed by fluctuations in amount of stuttering, and essentially no change in stuttering frequency. Ten of 12 participants showed no reduction in stuttering frequency during the experimental segment of the monologue task. These findings have ramifications both for the clinical utilization of FAF and for theoretical explanations of fluency-enhancement.

Adult↗
PubMed1998

Quantitative electroencephalogram of posterior cortical areas of fluent and stuttering participants during reading with normal and altered auditory feedback.

In the left and right hemisphere, posterior quantitative electroencephalogram Beta band activity (13.5-25.5 Hz) of seven adult participants who stutter and seven age-matched normal controls was obtained while subjects read text under three experimental conditions of normal auditory feedback, delayed auditory feedback, and frequency-altered feedback. Data were obtained from surface electrodes affixed to the scalp using a commercial electrode cap. Electroencephalogram activity was amplified, band-pass analog-filtered, and then digitized. During nonaltered auditory feedback, stuttering participants displayed Beta band hyperreactivity, with the right temporal-parietal lobe region showing the greatest activity. Under conditions of delayed auditory feedback and frequency-altered auditory feedback, the stuttering participants displayed a decrease in stuttering behavior accompanied by a strong reduction in Beta activity for the posterior-temporal-parietal electrode sites, and the left hemisphere posterior sites evidenced a larger area of reactivity. Such findings suggest than an alteration in the electrical fields of the cortex occurred in the stuttering participants under both conditions, possibly reflecting changes in neurogenerator status or current dipole activity. Further, one could propose that stuttering reflects an anomaly of the sensory-linguistic motor integration wherein each hemisphere generates competing linguistic messages at hyperreactive amplitudes.

Adolescent↗