bluuebunny/crossref_metadata_2025 huggingface dataset:
Binaural Release from Masking for a Speech Sound in Infants, Preschoolers, and Adults
Authors: Nozza Robert J. , Wagner Eric F. , Crandell Melissa A.
Published: July 2014

Binaural masked thresholds for a speech sound (/ba/) were estimated under two interaural phase conditions (N
0
S
0
and N
0
S
π
;) in three age groups (infants, preschool children, and adults). A computer-based head-turn with visual reinforcement procedure was used to test the infants. Preschoolers were tested using a modified play audiometry task, and adults were tested conventionally with the same apparatus as used with the infants. Differences in masked threshold as a function of both age and interaural phase condition, and differences in the binaural masking level difference (BMLD) with age, were found when the masker intensity was the same for each group. However, testing of adults with maskers of reduced intensity to compensate for hearing threshold differences relative to the two younger groups (a possible confounding variable in the estimate of the BMLD) eliminated the difference in BMLD between adults and preschoolers. The difference between infants and adults remained statistically significant, suggesting a possible developmental change in binaural hearing early in life. The relevance of developmental change in binaural hearing with respect to both infant auditory processing and the methods we use to assess it are discussed.
Use of Adaptive Digital Signal Processing to Improve Speech Communication for Normally Hearing and Hearing-Impaired Subjects
Authors: Harris Richard W. , Brey Robert H. , Robinette Martin S. , Chabries Douglas M. , Christiansen Richard W. , Jolley Ray G.
Published: July 2014

A two microphone adaptive digital noise cancellation technique was used to improve word-recognition ability of normally hearing and hearing-impaired subjects in the presence of varying amounts of multitalker speech babble noise and speech spectrum noise. Signal-to-noise ratios varied from -8 dB to + 12 dB in 4 dB increments. The adaptive noise cancellation technique resulted in reducing both the speech babble and speech spectrum noises 18 to 22 dB. This reduction in noise resulted in average improvements in word recognition, at the poorest signal-to-noise ratios, ranging from 37% to 50% for the normally hearing subjects and 27% to 40% for the hearing-impaired subjects. Improvements in word recognition in the presence of speech babble noise as a result of adaptive filtering were just as large or larger than improvements found in the presence of speech spectrum noise. The amount of improvement of word-recognition scores was most pronounced at the least favorable signal-to-noise ratios.
A Clinically Feasible Method for Determining Frequency Resolution
Authors: Davidson Stephanie A. , Melnick William
Published: July 2014

Psychophysical tuning curves were generated by normally hearing and hearing-impaired subjects using two methods; a detailed laboratory method and a Bekesy method proposed as suitable for clinical use. The two methods were compared for stability, the amount of masking produced and the pattern of the masking functions. The two measures of frequency resolution were found to be equally reliable and showed the same range of repeatability as simple pure tone thresholds. The patterns of the masking functions were similar regardless of the method used. However, the absolute amounts of masking indicated with each method were significantly different, with more masking obtained when the clinical method was used.
Criterion Validity of Speech Intelligibility Rating-Scale Procedures for the Hearing-Impaired Population
Authors: Samar Vincent J. , Metz Dale Evan
Published: July 2014

The criterion validity and reliability of two popular rating-scale procedures for the assessment of the contextual speech intelligibility of hearing-impaired individuals (The NTID Scales) were studied under clinically typical conditions of test administration and evaluation. The criterion measure was a write-down procedure based on subjects' readings of sentence lists chosen from The CID Everyday Sentence lists. Although the results revealed generally high overall validity and reliability coefficients for the two scales, a close examination of the distribution of estimation error over the full range of rating-scale values revealed gross violations of measurement prediction within the clinically most frequent midrange of speech intelligibility. The results indicate that the rating-scale procedure significantly compromises clinical and research classification of an individual's speech intelligibility and that write-down procedures may provide a viable and significantly more accurate alternative for speech intelligibility assessment.
Monitoring Vocal Fold Abduction through Vocal Fold Contact Area
Authors: Rothenberg Martin , Mahshie James J.
Published: July 2014

A number of commercial devices for measuring the transverse electrical conductance of the thyroid cartilage produce waveforms that can be useful for monitoring movements within the larynx during voice production, especially movements that are closely related to the time-variation of the contact between the vocal folds as they vibrate. This paper compares the various approaches that can be used to apply such a device, usually referred to as an electroglottograph, to the problem of monitoring the time-variation of vocal fold abduction and adduction during voiced speech. One method, in which a measure of relative vocal fold abduction is derived from the duty cycle of the linear-phase high pass filtered electroglottograph waveform, is developed in detail.
Coordination of Aerodynamic and Phonatory Processes in Fluent Speech Utterances of Stutterers
Authors: Peters Herman F. M. , Boves Louis
Published: July 2014

It has often been suggested that there is a close relation between problems in the coordination of respiratory, phonatory, and processes and dysfluencies in speech production. However, empirical support for this hypothesis is scarce, because most studies of speech behavior have been restricted to a single motor process. The present investigation examines the interactions of respiration (specifically the build up of subgloftal pressure), phonation, and articulation. Pressure build-up patterns preceding the onset of phonation were studied in 573 fluent utterances of 10 stutterers and in 552 utterances of 7 control subjects. Stutterers evidenced deviant patterns of subglottal pressure build-up much more often than did control speakers. Electroglot-tographic records of voice onset were classified as either abrupt or gentle and with respect to the presence or absence of gross irregularities in amplitude (shimmer) and period duration (jitter). Stutterers evidenced abrupt voice onsets significantly more often than did controls. The occurrence of jitter and shimmer, however, did not differ significantly across the groups. Acoustic measures of abruptness of voice onset, first syllable duration, and average syllable duration were also obtained, but they failed to differ significantly between the two groups. This study corroborates previous findings that perceptually fluent utterances of stutterers may differ, on a physiological level, from the speech of nonstutterers.
Variations in Velar Position over Time
Authors: Karnell Michael P. , Linville Raymond N. , Edwards Bonnie A.
Published: July 2014

Changes in velar position during production of nonnasal speech in two adults were measured using field-by-field videoendoscopic tracking procedures. The data suggested that the changes in velar position were coordinated with syllable production. Peak velar displacement occurred during maximum oral closure for oral consonant production and was followed by lowering of velar position during vowel production. This pattern of velar movement was not altered by changes in speaking rate or by jaw fixation. The timing of peak velar elevation relative to peak intraoral air pressure and peak jaw elevation was also examined. Timing of peak velar displacement was statistically associated with timing of peak intraoral air pressure in one subject. The data are discussed with regard to the potential value of studying variations in velar position during nonnasal speech in patients with marginal velopharyngeal incompetence.
Some Theoretical Considerations concerning the Relation between Functional Gain and Insertion Gain
Authors: Stelmachowicz Patricia G. , Lewis Dawna E.
Published: July 2014

Three examples in which insertion gain and functional gain measures of hearing aid response do not agree are illustrated. In two of the cases, functional gain measures overestimate the true real-ear gain for average conversational speech and in the third example, insertion gain measures are shown to provide an inaccurate estimate of aided benefit. Reasons for these discrepancies are discussed, and an alternative method for measuring real-ear hearing-aid response is described.
Spontaneous Speaking Fundamental Frequency of 6-Year-Old Black Children
Authors: Wheat Marica C. , Hudson Amelia I.
Published: July 2014

The fundamental vocal frequency characteristics were measured from 50 male and 50 female Black 6-year-old children during prompted spontaneous speech. Boys had a mean fundamental frequency of 219.50 Hz, with a mean range of 134.80–298.70 Hz. Girls had a mean fundamental frequency (F
0
) of 211.30 Hz and a mean frequency range of 137.60–297.50 Hz. No significant differences in mean or range values were found as a function of speaker sex. Nonsignificant relationships were found between physical variables of speaker height and weight and these F
0
measures for either sex and for the speaker group combined. The results of the present study were compared to previous research concerning the speaking fundamental vocal frequency of White children.
Direct Magnitude Estimation and Equal Appearing Interval Scaling of Vowel Roughness
Authors: Toner Mary Ann , Emanuel Floyd W.
Published: July 2014

Direct magnitude estimation (DME) and equal-appearing interval (EAI) ratings of the perceived roughness of isolated sustained vowel samples (/a/ and /i/) were obtained. The linear and curvilinear relationship between the resulting EAI and DME ratings was then examined. That relationship was found to be more strongly curvilinear than linear, a characteristic of a prothetic continuum. The amount of variance accounted for by a curvilinear model of the relationship, however, was minimally more than that accounted for by a linear model. The findings thus suggest that the roughness continuum manifests no more than "a little" protheticness, if any. It does not seem clear from this initial study that there is greater validity associated with roughness ratings obtained by the DME than the EAI method. Rather, the findings suggest that a small degree of such advantage may exist, but it may be too small to be of practical consequence in many instances.
A Comparative Investigation of the Laryngeal Premotor, Adjustment, and Reaction Times of Stutterers and Nonstutterers
Authors: Bakker Klaas , Brutten Gene J.
Published: July 2014

The laryngeal premotor, adjustment, and reaction times of 24 stutterers and 24 nonstutterers were assessed by means of a group (2) by stimulus modality (3) by stimulus order (6) factorial investigation. The laryngeal measures were determined from print outs made from electroglottographic recordings taken during the production of [] that was cued by a visual, auditory, or somato-sensory stimulus. The results revealed that the laryngeal reaction times of stutterers were significantly longer than those of the nonstutterers. Moreover, the reaction times were significantly longer both during the laryngeal premotor and adjustment time periods. The observed between-group difference for each of these laryngeal measures was independent of the stimulus that was employed.
Characteristics of Speech Breathing in Young Women
Authors: Hodge Megan M. , Rochet Anne Putnam
Published: July 2014

Chest wall kinematic records were obtained from 10 healthy young women in the upright, seated position during resting breathing, conversation, and reading aloud. Breathing frequency, lung volume levels relative to resting end-expiratory level, and relative volume displacements of the rib cage and abdomen were measured. Compared to conversation, group results for reading revealed three differences: an increase in syllables spoken per breath, an absence of filled pauses, and a slight upward shift in end-inspiratory and end-expiratory lung volume levels. Compared to resting breathing, group results for speech revealed four differences: a background chest wall configuration characterized by a relatively larger rib cage and smaller abdomen, slight increases in breathing frequency and in lung volume expenditure, and a slight decrease in rib cage contribution to lung volume displacement. The physical characteristic most strongly associated with rib cage contribution to lung volume displacement in resting breathing was height (r = .76). In comparing the relationship between the same respiratory behavior during resting breathing and speech, a correlation of .83 was obtained for rib cage contribution to volume displacement in the two conditions and of .60 for end-inspiratory volume level in the two conditions. Somewhat weaker positive correlations were obtained for lung volume expenditure and for breathing frequency in the two conditions. Comparison of the present findings for women to those recently reported for comparable men (Holt & Hixon, 1987) revealed no remarkable differences in speech breathing characteristics. Results suggest that certain physical characteristics and task variables may have greater functional importance than gender in determining normative speech breathing behaviors.
The Speech Regulating System
Authors: Warren Donald W. , Dalston Rodger M. , Morr Kathleen E. , Hairfield W. Michael , Smith Lynn R.
Published: July 2014

Temporal and respiratory responses to a loss of velar resistance were measured in 107 subjects demonstrating varying degrees of velopharyngeal inadequacy. The subject data were compared to data generated by a mechanical model representing a passive system. The pressure-flow technique was used to estimate velopharyngeal orifice size and measure respiratory and temporal characteristics of aerodynamic events associated with the production of the nasal-plosive blend/mp/in the word "hamper". Subjects were categorized as having adequate closure (<0.05 cm
2
), adequate/borderline closure (0.05–0.09 cm
2
), borderline/ inadequate closure (0.10–0.19 cm
2
) and inadequate closure (⩾ 0.20 cm
2
).

The data revealed that intraoral pressure fell 10-fold in the model as velopharyngeal orifice area changed from adequate closure to inadequate. The subject data demonstrated only a 1.4-fold drop in pressure. Airflow data indicated that there was a 10-fold increase in respiratory volume in the subject data corresponding to the change from adequacy to inadequacy. When respiratory and temporal responses were assessed together, the findings revealed that airflow and temporal changes minimized the fall of pressure as velar resistance declined across groups.
Preliminary Evaluation of a Weibull Function for Fitting Slow-Component Eye Velocity over the Time Course of Caloric-Induced Nystagmus
Authors: Formby C. , Albritton B. , Rivera I. M.
Published: July 2014

We describe preliminary attempts to fit a mathematical function to the slow-component eye velocity (SCV) over the time course of caloric-induced nystagmus. Initially, we consider a Weibull equation with three parameters. These parameters are estimated by a least-squares procedure to fit digitized SCV data. We present examples of SCV data and fitted curves to show how adjustments in the parameters of the model affect the fitted curve. The best fitting parameters are presented for curves fit to 120 warm caloric responses. The fitting parameters and the efficacy of the fitted curves are compared before and after the SCV data were smoothed to reduce response variability. We also consider a more flexible four-parameter Weibull equation that, for 98% of the smoothed caloric responses, yields fits that describe the data more precisely than a line through the mean. Finally, we consider advantages and problems in fitting the Weibull function to caloric data.
Perception/Production Relationships in the Development of the Vowel Duration Cue to Final Consonant Voicing
Authors: Lehman Mark E. , Sharf Donald J.
Published: July 2014

The purposes of this study were to assess: (a) the development of identification and discrimination in children for the vowel duration cue to final consonant voicing and (b) the perception/production relationships in children for the vowel duration cue to final consonant voicing. Subjects were 30 children divided equally into three age groups, and 10 adults. Productions consisted of 15 repetitions of two target syllables (beet, bead) analyzed acoustically for vowel duration. From these were calculated category boundary, category separation, and variability in production for each subject. Perceptual data were collected using a synthesized speech continuum that varied vowel duration. Identification responses were used to calculate category boundary, category separation (slope/boundary width) and variability (response consistency) for each subject. Mean percentage correct discrimination was derived by using two-step and three-step two-pair same-different paradigms. The results were as follows: (a) category boundary and category separation in production were adult-like by 8 years of age, (b) variability in production was not adult-like by 10 years of age, (c) perception categorization (category boundary and category separation) was adult-like at 5 years of age, (d) perceptual consistency was not adult-like until 10 years of age, (e) percentage correct discrimination was not adult-like by 10 years of age, (f) correlations between comparable perception and production measures were nonsignificant, and (g) a pairwise comparisons analysis indicated that perception was consistently more advanced than production.
Analytic Study of the Tadoma Method
Authors: Reed Charlotte M. , Durlach Nathaniel I. , Braida Louis D. , Schultz Martin C.
Published: July 2014

In the Tadoma method of communication, deaf-blind individuals receive speech by placing a hand on the face and neck of the talker and monitoring actions associated with speech production. Previous research has documented the speech perception, speech production, and linguistic abilities of highly experienced users of the Tadoma method. The current study was performed to gain further insight into the cues involved in the perception of speech segments through Tadoma. Small-set segmental identification experiments were conducted in which the subjects' access to various types of artieulatory information was systematically varied by imposing limitations on the contact of the hand with the face. Results obtained on 3 deaf-blind, highly experienced users of Tadoma were examined in terms of percent-correct scores, information transfer, and reception of speech features for each of sixteen experimental conditions. The results were generally consistent with expectations based on the speech cues assumed to be available in the various hand positions.
Closed-Set Effects in Consonant Confusion Patterns
Authors: Bell Theodore S. , Dirks Donald D. , Kincaid Gail E.
Published: July 2014

Invariance of error patterns in confusion matrices of varying dimensions were examined. Normal-hearing young adults were presented closed-set arrangements of digitized syllable tokens, spoken by 1 male and 1 female talker, and selected from a set of 14 consonants (stops and fricatives). Each consonant was paired with the vowel /a/ in a vowel-consonant format and presented at three intensity levels. Patterns of errors among voiceless stops and among voiced fricatives were dependent on the set of alternatives. Voiceless fricatives and voiced stops were not significantly affected by the number of response alternatives. Speaker differences, individual differences among listeners, and implications relating to the generalization of confusion data collected in small closed-set arrangements arc discussed.
Speech Breathing in Children and Adolescents
Authors: Hoit Jeannette D. , Hixon Thomas J. , Watson Peter J. , Morgan Wayne J.
Published: July 2014

An investigation was conducted to elucidate the nature of speech breathing in children and adolescents and to determine if sex and age influence performance. Eighty healthy boys and girls representing four age groups (7, 10, 13, and 16 years) were studied using helium dilution to obtain measures of subdivisions of the lung volume and using magnetometers to obtain measures of resting tidal breathing and speech breathing. Results for subdivisions of the lung volume and resting tidal breathing revealed sex- and age-related differences, most of which were attributable to differences in breathing apparatus size. Results for speech breathing indicated that sex was not an important variable, but that age was critical in determining speech breathing performance. The most substantial differences were between the 7-year-old group and older groups. These differences were characterized by larger lung volume, rib cage volume, and abdominal volume initiations and terminations for breath groups, larger lung volume excursions per breath group, fewer numbers of syllables per breath group, and larger lung volume expenditures per syllable for the 7-year-old group compared to older groups. In most respects, speech breathing appeared adultlike by the end of the first decade of life. Clinical implications regarding these findings are offered.
Modulation Transfer Functions
Authors: Scott Diane M. , Humes Larry E.
Published: July 2014

Modulation transfer functions (MTFs) were measured with three different psychoacoustical paradigms in the same normal-hearing subjects. In the temporal-probe method, the threshold of a 4-ms probe tone (frequencies of 1000 and 4000 Hz) was measured at various envelope phases within a 100% sinusoidally amplitude-modulated (SAM) noise at modulation frequencies from 2 to 256 Hz. For the derived-MTF method, the threshold of a 500-ms tone at 1000 and 4000 Hz was measured in the same noise at the same modulation frequencies. For the modulation-detection paradigm, modulation thresholds were measured as a function of modulation frequency for bandpass filtered SAM noise centered at 1000 and 4000 Hz. MTFs with lowpass shapes were observed with all three methods. Differences were observed in the cutoff frequencies and/or attenuation rates when the data were fitted with lowpass filter transfer functions. Factors influencing those differences are discussed.
On Prognostic Research in Adult Neurologic Disorders
Authors: Tompkins Connie A. , Jackson Susan T. , Schulz Richard
Published: July 2014

This note suggests some changes in variable selection and operationalization for research on prognosis in adult neurologic communicative disorders. The issues raised are relevant to both broad prognostic questions concerning extent of recovery, and focused questions regarding candidacy and treatment efficacy.
Response to Gierut, Elbert, & Dinnsen (1987)
Authors: Tomes Lucrezia
Published: July 2014

Further analysis of the data presented by Gierut et al. showed that some similar patterns of change for untreated sounds were characteristic of subjects in both groups. These similarities make the performances of the two groups less different than Gierut et al. indicated. The patterns of change observed in subjects from both groups may involve maturation, relationships among cognates, or some general effect of treatment. Furthermore, the present analysis supported the conclusion of Gierut et al. that the performance of subjects from the two groups
did
differ in some respects. However, these differences may be related to other factors not identified by Gierut et al.: (a) subject variables, or (b) the number of opportunities subjects had to make changes in cognates of targets and to make changes in cognates of untreated sounds that were associated with high pretreatment knowledge. As Gierut et al. were careful to point out, further studies of the effect of target choice on changes in the phonological system are needed. Future research should attempt to rule out the potentially confounding factors identified here.
Selected Acoustic Characteristics of Voices Before Intubation and After Extubation
Authors: Horii Yoshiyuki , Fuller Barbara F.
Published: July 2014

Effects of endotracheal intubation on acoustic characteristics of voices were investigated for 8 male and 8 female subjects using a miniature neck accelerometer and computerized analysis methods. Variables extracted from sustained vowels were (1) spectral slopes of the average waveforms, (2) harmonics-to-noise ratios (H/N), (3) coefficients of variation for amplitude (CVA), (4) coefficients of variation for fundamental frequency (CVF), (5) amplitude perturbation (shimmer), and (6) fundamental frequency perturbation (jitter). Fundamental frequency (Fo) distributional statistics (mean Fo, Fo standard deviation, and Fo mid-90% range) were also obtained from oral readings. Results for the sustained vowel samples showed that after extubation, (1) spectral slopes were less steep, and (2) both shimmer and jitter were greater than before intubation. Results for the passage reading revealed that the mean Fo was lower and the Fo standard deviation and mid-90% range were smaller after the extubation than before intubation. It was concluded that even short-term endotracheal intubation affects acoustic characteristics of voice and that selected measures of waveform characteristics are sensitive enough to reveal such effects.
Critical Differences in Aided Sound Field Thresholds in Children
Authors: Stuart Andrew , Durieux-Smith Andrée , Stenstrom Robert
Published: July 2014

Variability of aided sound field thresholds (ASFTs) was examined in 30 children comprising two age groups (5–9 and 10–14 years). Test-retest ASFTs were collected at six frequencies (250, 500, 1000, 2000, 3000, and 4000 Hz). No statistically significant difference was found in mean test and retest ASFTs between the two groups (
p
> .05). Test-retest difference data from both groups of children were combined and used to generate critical differences (in dB) for two ASFTs. At a 95% confidence level, two ASFTs would have to differ by more than 10 dB across signal test frequencies to attain statistical significance. In clinical decision-making, if one accepts smaller differences in ASFTs as statistically significant, larger probabilities of error must be assumed.
Ramp-and-Hold Force Control in the Upper and Lower Lips
Authors: Barlow Steven M. , Burton Mary K.
Published: July 2014

The relation among several parameters of the ramp-and-hold force contraction and target force level was quantified for the upper and lower lip in 40 normal adults and in 4 young adults who had sustained traumatic brain injury (TBI). Using visual feedback, subjects produced ramp-and-hold compression lip forces as rapidly and accurately as possible to end-point target levels ranging from 0.25 to 2.00 newtons. In normal adults, significant positive linear relations were found between the parameters of the ramp-and-hold lip force task and target force level, including the peak rate of force change, peak force, and the mean and standard deviation of force during the hold phase. Though males and females have been shown to differ greatly on absolute maximum force-generating capabilities, they are virtually identical on the measures used to quantify the lip force ramp-and-hold task over the range of compression forces studied. Preliminary investigation of lip force control in 4 TBI subjects suggests that these quantitative measures are useful in determining the distribution and nature of motor impairment between the upper and lower lips during a dynamic force control task.
Muscle Spindles in the Human Levator Veli Palatini and Palatoglossus Muscles
Authors: Liss Julie M.
Published: July 2014

Muscle spindles are present in many muscles of the speech mechanism including those of the jaw, tongue, larynx, and respiratory system. Past investigations that have examined muscles of the velopharynx for the presence of muscle spindles have reported their existence only in the tensor veli palatini and palatoglossus muscles. The present investigation has demonstrated the existence of muscle spindles in two muscles of the human velopharynx—the levator veli palatini (LVP) and palatoglossus muscles. Seven LVP and two palatoglossus muscles were embedded in paraffin blocks, serially sectioned at 8 microns, and selected slides were stained by a modified Gomori trichrome technique. Scanning by light microscopy at 40x revealed spindles in all of the muscles examined. This positive finding likely reflects the use of a more chromatically distinctive staining procedure and a higher scanning magnification than were used in prior investigations. The potential roles of muscle spindles in velopharyngeal function are addressed.
Acoustic Measurements of Men’s and Women’s Voices
Authors: Nittrouer Susan , McGowan Richard S. , Milenkovic Paul H. , Beehler Donna
Published: July 2014

Several acoustic measures of laryngeal activity were made on adult speech to help answer two questions left unresolved by previous work: (1) how each measure varies, if at all, with phonetic structure, and (2) what aspect of laryngeal activity each measure specifies. Speech samples of 15 syllables (three vowels in five prevocalic consonantal contexts) were collected from men and women at two times of the day (early morning and late afternoon). Eight measurements were made, mainly on slices extracted from the middle of the vocalic portions, and inferential and correlational statistics were applied to these measures. Results of the inferential tests indicated differences between men and women in how laryngeal adjustments are made, affecting relative amounts of vocal jitter and spectral tilt of the voicing source. In addition, the voicing and manner characteristics of the prevocalic consonant were found to affect fundamental frequency, cycle-to-cycle perturbations, and amount of aspiration noise. To a lesser extent, vowel height and front/back tongue placement also affected these acoustic source characteristics. Results of the correlational tests showed that different laryngeal mechanisms contributed differentially to signal-to-noise ratios for men and women, and these mechanisms were more greatly affected by fundamental frequency for men’s samples. Finally, various acoustic measures of laryngeal noise were found to be related to the same underlying mechanism.
Observational Learning of Comprehension Monitoring Skills in Children Who Exhibit Mental Retardation
Authors: Ezell Helen K. , Goldstein Howard
Published: July 2014

An observational learning paradigm was used to instruct 5 children with mild or moderate mental retardation to monitor their comprehension of inadequate instructions. Instructions were inadequate because of an interfering signal, an unfamiliar word, excessive length, or an unfamiliar idiomatic phrase. Subjects’ peers served as models during the training. A multiple baseline design across subjects and across instruction types was employed. All subjects learned to request clarification of the first three inadequate instructions; however, none of the children learned to request clarification of idiomatic phrases. Although all children eventually demonstrated observational learning, three children required feedback from the trainer before they began to request clarification for one or two of the instruction types. Two children generalized their requesting behavior to the interfering signal message type, suggesting that generalization may be likely to occur between similar message types. During posttesting all children generalized their requesting behavior when presented with two unfamiliar message types, sometimes using new question forms. Four of the 5 children also generalized their requesting behavior in sessions with their teachers 5–10 weeks later.
The Effect of Direct Selection and Circular Scanning on Visual Sequential Recall
Authors: Mizuko Mark , Esser Joan
Published: July 2014

The purpose of this study was to investigate the influence of selection techniques on visual sequential recall. Specifically, this study investigated whether there are visual sequential recall differences between direct selection and scanning in task performance in normally developing 4-year-old children. Results suggested that there were no significant differences between direct selection and scanning for visual sequential recall. However, subjects correctly recalled significantly fewer symbols in a specific sequence represented by Blissymbols than by Picsyms. In addition they recalled significantly fewer three-symbol sequences than two-symbol sequences regardless of the type of symbol set.
Poststroke Depression
Authors: Swindell Carol S. , Hammons Jo-Ann
Published: July 2014

Poststroke depression is a serious disorder that can compromise the overall rehabilitative process, including speech-language treatment. To provide patients with the maximum opportunity for recovery and therapeutic gains, speech-language pathologists need to increase their awareness of depression and understand the neurologic, physiologic, diagnostic, and treatment implications of this disorder. This article defines depression and reviews the theories that explain the nature of the disorder as well as methods for diagnosing and treating stroke patients who are clinically depressed.
The Iowa Articulation Norms Project and Its Nebraska Replication
Authors: Smit A. B. , Hand L. , Freilinger J. J. , Bernthal J. E. , Bird A.
Published: July 2014

The Iowa Articulation Norms Project and Its Nebraska Replication. Smit, A. B., Hand, L., Freilinger, J. J., Bernthal, J. E., & Bird, A.
JSHD
, November 1990, 779–798.

The captions for Figures 20, 21, 22, and 23 on p. 793 were switched with those for Figures 24, 25, 26, and 27 on p. 794. In Table 7, p. 795, the numbers of the first eight figures listed under the heading “Word-initial clusters” should be 24, 25, 26, 27, 20, 22, 21, and 23.
Reliability and Validity of Infant Speech-Sound Discrimination-in-Noise Thresholds
Authors: Nozza Robert J. , Miller Sandra L. , Rossman Reva N. F. , Bond Linda C.
Published: July 2014

Infants were tested on a speech-sound discrimination-in-noise task using the visual reinforcement infant speech discrimination (VRISD) procedure with an adaptive (up-down) threshold protocol. An adult control group was tested using the same stimuli and apparatus. The speech sounds were synthetic /ba/ and /ga/. The masker was band-passed noise presented continuously at 48 dB SPL. Test-retest reliability was good for both groups, although test-retest differences were smaller for adults. For infants the mean of the absolute values of the differences between tests was only 5.2 dB, and there was less than a 10-dB difference between the two tests of 14 (87.5%) of the 16 infants completing the study. The infant-adult difference in discrimination threshold in noise was 6.9 dB, which agrees well with detection-in-noise thresholds from earlier studies and with discrimination-in-noise thresholds obtained on a subset of subjects in our earlier work. Advantages of the adaptive threshold procedure and its possible applications both in research studies and in the clinic are discussed.
Prediction of Deterioration in Hearing due to Hearing Aid Use
Authors: Macrae John H.
Published: July 2014

There is a definite risk of overamplification by hearing aids. Guidelines should therefore be established that will minimize the risk of damage to hearing involved in hearing aid use. A mathematical model that can be used for this purpose is derived from equations for predicting noise-induced permanent threshold shift given in International Standard ISO 1999 combined with the Modified Power Law. The model implies that any noise exposure that would cause deterioration of the hearing threshold levels of a person with normal hearing would also be harmful to the hearing of a person with sensorineural hearing impairment. It follows that, in order to ensure that no deterioration occurs in the hearing of a hearing aid user, the output levels from the aid must be such that they would not cause any damage to a person with normal hearing. This constraint can be met for hearing aid users with mild-to-moderate sensorineural hearing loss but cannot be met for users with severe-to-profound loss because it would result in the provision of insufficient gain, particularly at the higher frequencies. If the model is valid, then for this group, some appropriately small amount of hearing damage must be accepted as the cost of the advantages gained from the use of a hearing aid. Verification of the model is essential before the model is used in clinical practice to determine the risk of deterioration in hearing due to hearing aid use.
Respiratory and Laryngeal Function During Whispering
Authors: Stathopoulos Elaine T. , Hoit Jeannette D. , Hixon Thomas J. , Watson Peter J. , Solomon Nancy Pearl
Published: July 2014

Established procedures for making chest wall kinematic observations (Hoit & Hixon, 1987) and pressure-flow observations (Smitheran & Hixon, 1981) were used to study respiratory and laryngeal function during whispering and speaking in 10 healthy young adults. Results indicate that whispering involves generally lower lung volumes, lower tracheal pressures, higher translaryngeal flows, lower laryngeal airway resistances, and fewer syllables per breath group when compared to speaking. The use of lower lung volumes during whispering than speaking may reflect a means of achieving different tracheal pressure targets. Reductions in the number of syllables produced per breath group may be an adjustment to the high rate of air expenditure accompanying whispering compared to speaking. Performance of the normal subjects studied in this investigation does not resemble that of individuals with speech and voice disorders characterized by low resistive loads.
Respiratory Kinematics in Speakers with Cerebellar Disease
Authors: Murdoch Bruce E. , Chenery Helen J. , Stokes Peter D. , Hardcastle William J.
Published: July 2014

The respiratory abilities of a group of 12 speech disordered subjects with cerebellar disease were assessed using both spirometric and kinematic techniques and compared to those of a group of 12 non-neurologically impaired controls matched for age and gender. Results of the spirometric assessment showed that although all of the cerebellar-diseased subjects had normal total lung capacities, almost half had vital capacities below normal limits. All except 1 of the cerebellar-diseased subjects exhibited irregularities in their chest wall movements while performing sustained vowel and syllable repetition tasks. Over half of the cerebellar-diseased subjects also displayed similar rregularities when reading and conversing. The same irregularities were not present in the chest wall movements exhibited by the control subjects suggesting that their presence was caused by the cerebellar disease Results are discussed in terms of the effects of cerebellar disease on neuromuscular function.
Redundancy Enhances Emotional Inferencing by Right- and Left-Hemisphere-Damaged Adults
Authors: Tompkins Connie A.
Published: July 2014

This study investigated the influence of enhanced textual redundancy on affective interpretations made by unilaterally right or left hemisphere brain-damaged adults and normally aging control subjects. Emotional inferences were drawn from linguistic or prosodic material, and redundancy effects were examined within and across stimulus boundaries. Results indicate that heightened semantic redundancy improved the accuracy of linguistic and prosodic judgments of affect for all groups. Correct prosodic judgments were also made more quickly by a subset of each group when textual redundancy was maximized. The facilitory influence of increased redundancy was not attributable solely to perseveration or response rigidity. Possible mechanisms by which semantic redundancy affects cognitive processing are considered.
Effects of Thermal Application on Dysphagia After Stroke
Authors: Rosenbek John C. , Robbins JoAnne , Fishback Barbara , Levine Ross L.
Published: July 2014

The influence of thermal application on dysphagia for liquid boluses after multiple cerebrovascular accidents was measured. A month-long trial of thermal application organized according to the guidelines of a single-subject withdrawal or ABAB design was replicated across 7 male subjects. After baseline testing, 6 subjects were randomly assigned to begin the study with a week-long period of thermal application (B stage), and 1 subject was randomly assigned to begin the study with a week-long period of no thermal application (A stage). Subsequent week-long A and B stages were then alternated until each subject had completed the 4-week interval of this study. Progress testing occurred at the end of each stage and at follow-up testing 1 month after the study’s completion. The influence of thermal application on eight duration and four descriptive measures was determined by three judges using visual inspection of data displays. Two of three judges agreed that 2 of the subjects demonstrated decreased Duration of Stage Transition in the absence of any change in the occurrence of aspiration or penetration. Overall, this study failed to reveal strong evidence that 2 weeks of thermal application alternating with 2 weeks of no thermal application improves dysphagia following multiple strokes. Further replications are needed.
Perseveratory Coarticulation in the Speech of Profoundly Hearing-Impaired and Normally Hearing Children
Authors: Baum Shari R. , Waldstein Robin S.
Published: July 2014

This study investigated the extent of perseveratory coarticulation in the VC syllables [i∫, u∫, it, ut, ik, uk] as produced by 7- and 10-year-old normally hearing and profoundly hearing-impaired children. Measures of both temporal and spectral (centroid and F2 frequency) parameters were computed. The data revealed that the hearing-impaired speakers exhibited measurable but smaller effects of perseveratory coarticulation relative to the normally hearing speakers. These results are compared with studies of anticipatory coarticulation and are discussed in relation to the claim that perseveratory coarticulation is largely a result of the inertial properties of the speech production mechanism.
Consonant-Recognition Patterns and Self-Assessment of Hearing Handicap
Authors: Hustedde Carol Goldschmidt , Wiley Terry L.
Published: July 2014

Two companion experiments were conducted with normal-hearing subjects and subjects with high-frequency, sensorineural hearing loss. In Experiment 1, the validity of a self-assessment device of hearing handicap was evaluated in two groups of hearing-impaired listeners with significantly different consonant-recognition ability. Data for the Hearing Performance Inventory—Revised (Lamb, Owens, & Schubert, 1983) did not reveal differences in self-perceived handicap for the two groups of hearing-impaired listeners; it was sensitive to perceived differences in hearing abilities for listeners who did and did not have a hearing loss. Experiment 2 was aimed at evaluation of consonant error patterns that accounted for observed group differences in consonant-recognition ability. Error patterns on the Nonsense-Syllable Test (NST) across the two subject groups differed in both degree and type of error. Listeners in the group with poorer NST performance always demonstrated greater difficulty with selected low-frequency and high-frequency syllables than did listeners in the group with better NST performance. Overall, the NST was sensitive to differences in consonant-recognition ability for normal hearing and hearing-impaired listeners.
Measurement of Communicative Intentions in Normally Developing Children During Structured and Unstructured Contexts
Authors: Wetherby Amy M. , Rodriguez Gary P.
Published: July 2014

The purpose of this study was to examine the effect of sampling context on measurements of communicative intentions expressed by 15 normally developing children during the prelinguistic, one-word, and multiword stages. A communication sample using both structured and unstructured contexts was collected from each subject as he or she interacted with a clinician and parent at each language stage. Direct comparisons were made between the uses of requests and comments during the structured and unstructured sampling contexts. The results indicated that the mean number of requests and comments increased significantly from the prelinguistic to the multiword stage in both contexts. Significantly more requests were used during the structured context, but no significant difference was found between the numbers of comments used in the two contexts. Factors to consider in sampling communication from developmentally young children are discussed.
Auditory Distortion Products Measured With Averaged Auditory Evoked Potentials
Authors: Chertoff Mark E. , Hecox Kurt E. , Goldstein Robert
Published: July 2014

The purpose of this investigation was to describe the properties of averaged auditory evoked potential distortion products (AEP-DPs) in guinea pigs. This study provided a step toward developing a clinical index of nonlinear processing of auditory signals and supplied a baseline for studies evaluating the effect of cochlear damage on AEP-DPs.

The amplitude of the AEP-DPs was evaluated as a function of f2/fl ratio (1.12–1.52) and primary frequency (500 Hz–2000 Hz). The amplitude of the AEP cubic difference tone (AEP-CDT) increased with increasing f2/fl ratio for the 500-Hz f1 primary and remained constant for the 800-Hz and 1700-Hz f1 primaries. The AEP-CDT generated by the 1100-Hz and 1400 Hz f1 primaries was maximum for the middle f2/fl ratios (1.22, 1.32, and 1.42). The AEP-CDT could not be distinguished from the noise floor for the 2000-Hz f1 primary. The AEP difference tone (AEP-DT) was larger and more frequently identified than the AEP-CDT. The amplitude of the AEP-DT decreased with an increase in f2/f1 ratio. The decrease was more pronounced for low-frequency f1 primaries than for high-frequency f1 primaries.
Comparing Tongue Positioning by Normal-Hearing and Hearing-Impaired Children During Vowel Production
Authors: Dagenais Paul A. , Critz-Crosby Paula
Published: July 2014

Glossometric measures of tongue positions of 10 normal-hearing (NH) and 10 profoundly hearing-impaired (HI) children were compared during production of the eight vowels /i,
I
,ε,æ,u,U,o,a/. The NH subjects used tongue positions with distinct vertical distances from the hard palate and discrete tongue shapes to distinguish the front vowels and the back vowels. The HI subjects produced vowels using a reduced vertical range and singular flat, high-back tongue shape. Token-to-token variability was greater for the HI subjects. Listener identifications of the vowels produced by the HI subjects fell in three categories: highly variable responses to /i/, low vowels for /I,ε,æ,a/, and back vowels for /u,U,o/. The centralized, generally undifferentiated tongue positions and listener identifications for the HI subjects coincided with suppositions made from previous perceptual, acoustic, and physiologic findings.