bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation Detection Interference in Listeners With Normal and Impaired Hearing
Authors: Bacon Sid P. , Opie Jane M.
Published: April 2006

Listeners were asked to detect amplitude modulation (AM) of a target (or signal) carrier that was presented in isolation or in the presence of an additional (masker) carrier. The signal was modulated at a rate of 10 Hz, and the masker was unmodulated or was modulated at a rate of 2, 10, or 40 Hz. Nine listeners had normal hearing, 4 had a bilateral hearing loss, and 4 had a unilateral hearing loss; those with a unilateral loss were tested in both ears. The listeners with a hearing loss had normal hearing at 1 kHz and a 30- to 40-dB loss at 4 kHz. The carrier frequencies were 984 and 3952 Hz. In one set of conditions, the lower frequency carrier was the signal and the higher frequency carrier was the masker. In the other set, the reverse was true. For the impaired ears, the carriers were presented at 70 dB SPL. For the normal ears, either the carriers were both presented at 70 dB SPL or the higher frequency carrier was reduced to 40 dB SPL to simulate the lower sensation level experienced by the impaired ears. There was considerable individual variability in the results, and there was no clear effect of hearing loss. These results suggest that a mild, presumably cochlear hearing loss does not affect the ability to process AM in one frequency region in the presence of competing AM from another region.
Speech Segmentation by Native and Non-Native Speakers
Authors: Sanders Lisa D. , Neville Helen J. , Woldorff Marty G.
Published: April 2006

Varying degrees of plasticity in different subsystems of language have been demonstrated by studies showing that some aspects of language are processed similarly by native speakers and late-learners whereas other aspects are processed differently by the two groups. The study of speech segmentation provides a means by which the ability to process different types of linguistic information can be measured within the same task, because lexical, syntactic, and stress-pattern information can all indicate where one word ends and the next begins in continuous speech. In this study, native Japanese and native Spanish late-learners of English (as well as near-monolingual Japanese and Spanish speakers) were asked to determine whether specific sounds fell at the beginning or in the middle of words in English sentences. Similar to native English speakers, late-learners employed lexical information to perform the segmentation task. However, nonnative speakers did not use syntactic information to the same extent as native English speakers. Although both groups of late-learners of English used stress pattern as a segmentation cue, the extent to which this cue was relied upon depended on the stress-pattern characteristics of their native language. These findings support the hypothesis that learning a second language later in life has differential effects on subsystems within language.
Morehead & Ingram (1973) Revisited
Authors: Ingram David , Morehead Donald
Published: April 2006

The finding in Morehead and Ingram (1973) that children with a language impairment do better in the use of inflectional morphology than MLU-matched typically developing children has been in marked contrast to several subsequent studies that have found the opposite relationship (cf. review in Leonard, 1998). This research note presents a reanalysis of a subset of the original Morehead and Ingram data in an attempt to reconcile these contradictory findings. The reanalysis revealed that the advantage on inflectional morphology for children with language impairment was only on the progressive suffix, not on plural and possessive or on the verbal morphemes third-person present tense and past tense. The results of the reanalysis are in line with more recent research (e.g., Rice, Wexler, & Cleave, 1995). The resolution of these discrepant results highlights the critical roles that methodological issues play—specifically, how subjects are matched on MLU, how inflectional morphology is measured, and the selection of subjects with regard to age.
Tongues and Lips Without Jaws
Authors: Westbury John R. , Lindstrom Mary J. , McClean Michael D.
Published: April 2006

Speech-related motions of small markers attached to the tongue, lower lip, and lower jaw of 44 normal young adult talkers of American English were analyzed to estimate the relative accuracy of selected methods for decoupling tongue and lip motions from ongoing jaw motion when all movements are originally measured relative to a common reference frame (such as the head). In general, results of the analysis show that a common "simple subtractio" method that ignores pitching rotation of the jaw yields larger errors in positions and speeds of decoupled tongue and lip markers than methods that do not ignore rotation. When the jaw is widely opened, is moving quickly, and/or when any decoupled marker is relatively far from the origin of a local coordinate system fixed to the jaw, positional and speed errors associated with the subtraction method can exceed 5 mm and 25 mm/s, respectively. We propose a simple procedure for estimating the pitching rotation of the jaw that can be applied when pitch cannot be measured. We then show that decoupled motions of tongue and lower lip markers based on estimated jaw rotation involve less error than those derived from any other decoupling method considered. Careful attention to processing methods should yield more accurate inferences about the nature and degree of coordination between speech-related movements of the tongue and lower lip that are decoupled from, and hence independent of, concurrent movements of the lower jaw.
Articulatory Control of Vowel Length for Contiguous Jaw Cycles
Authors: Shaiman Susan
Published: April 2006

The current study examined contiguous cycles of jaw movement in order to determine if select suprasegmental manipulations operate globally across the entire utterance, while phonetic changes are more locally administered. Specifically, articulatory kinematics were examined to determine if intra- and interarticulatory spatial and temporal organization across manipulations of speaking rate was maintained for both jaw cycles while differing between the two cycles for phonetic changes (i.e., in coda composition) specific to the second jaw cycle. Five normal speakers repeated the syllables /pæp/, /pæps/, and /pæpst/, embedded in the carrier phrase, ‘Now say — again,’ using slow, normal, and fast speaking rates. Measures were made of the magnitude of jaw opening peak velocity and time to peak velocity, as well as of coarticulatory overlap and interarticulator timing, for the first jaw cycle (jaw lowering for /eI/ in ‘say’ to the first /p/) and the second jaw cycle (jaw lowering for /æ/ to the second /p/). The current data indicate that, for intra-articulatory kinematics, the manipulation of phonetic context resulted in localized adjustments, whereas the manipulation of speaking rate was applied globally across the utterance. Conversely, for interarticulatory kinematics, the upper lip-jaw synergy was reconfigured across the utterance for manipulations of speaking rate, whereas this synergy was maintained for localized manipulations in phonetic context. Results are discussed with respect to motor strategies being flexibly implemented as a result of contextual variation and speech rate.
Profiles of Grammatical Morphology and Sentence Imitation in Children With Specific Language Impairment and Down Syndrome
Authors: Eadie P. A. , Fey M. E. , Douglas J. M. , Parsons C. L.
Published: April 2006

The purpose of the present study was to examine the grammatical morphology and sentence imitation performance of two different groups of children with language impairment and to compare their performance with that of children learning language typically. Expressive use of tense-bearing and non-tenserelated grammatical morphemes was explored. Children with specific language impairment (SLI), with Down syndrome (DS), and with typical language development (TL) were matched on mean length of utterance (MLU). Performance was compared primarily on composite measures of tense, tense inflections, and nontense morphemes, as well as on the Sentences subtest of the Wechsler Preschool and Primary Scale of Intelligence—Revised (WPPSI-R; D. Wechsler, 1989). Exploratory analyses were completed on a set of 11 individual grammatical morphemes as a follow-up to the principal analyses. As predicted, the children with SLI performed significantly more poorly than the children with TL on all three composite measures. In addition, the DS group exhibited significantly weaker performance than did the TL group on the tense inflections and non-tense morpheme composites. Although there were no statistically reliable differences between the SLI and DS groups on any morpheme measure, the groups were not comparably weak in their use of the regular past, -ed; the irregular third person singular morphemes (e.g., has, does); the present progressive, -ing; or the use of modals. The SLI and DS groups both performed more poorly than did the TL group on the sentence imitation task.
Production Operations and the Use of Nonfinite Verbs by Children With Specific Language Impairment
Authors: Leonard Laurence B. , Miller Carol A. , Deevy Patricia , Rauf Leila , Gerber Erika , Charest Monique
Published: April 2006

Recent evidence from structural priming studies suggests that children with specific language impairment (SLI) are more likely to produce verb morphemes such as auxiliary
is
when their previous sentence contained an auxiliary than when it did not. The same paradigm was employed in the present study to determine whether failures to include auxiliary
is
might be due to prior use of nonfinite sentences (e.g.,
The mouse eating the cheese
). Preschoolers with SLI and a group of younger normally developing children were more likely to produce auxiliary
is
to describe target pictures when the preceding sentence contained auxiliary
are
than when it contained past tense. Use of
is
in the target sentence was least likely when the preceding sentence was nonfinite. The implications of these findings for current accounts of SLI and current models of sentence production are discussed.
The Influence of Pitch and Loudness Changes on the Acoustics of Vocal Tremor
Authors: Dromey Christopher , Warrick Paul , Irish Jonathan
Published: April 2006

The effect of tremor on phonation is to modulate an otherwise steady sound source in its amplitude, fundamental frequency, or both. The severity of untreated vocal tremor has been reported to change under certain conditions that may be related to muscle tension. In order to better understand the phenomenon of vocal tremor, its acoustic properties were examined as individuals volitionally altered their pitch and loudness. These voice conditions were anticipated to alter the tension of the intrinsic laryngeal muscles. The voices of 10 individuals with a diagnosis of vocal tremor were recorded before participating in a longitudinal treatment study. They produced vowels at low and high pitch and loudness levels as well as in a comfortable voice condition. Acoustic analyses quantified the amplitude and frequency modulations of the speakers' voices across the various conditions. Individual speakers varied in the way the pitch and loudness changes affected their tremor, but the following statistically significant effects for the speakers as a group were observed: Higher pitch phonation was associated with a more rapid rate for both amplitude and frequency modulations. Amplitude modulation became faster for louder phonation. Low-pitched phonation led to decreases in the extent of amplitude tremor. Varying pitch led to dramatic changes in the phase relationship between amplitude and frequency modulation in some of the speakers, whereas this effect was not apparent in other speakers.
Predicting Longitudinal Change in Language Production and Comprehension in Individuals With Down Syndrome
Authors: Chapman Robin S. , Hesketh Linda J. , Kistler Doris J.
Published: April 2006

Longitudinal change in syntax comprehension and production skill, measured four times across a 6-year period, was modeled in 31 individuals with Down syndrome who were between the ages of 5 and 20 years at the start of the study. Hierarchical Linear Modeling was used to fit individual linear growth curves to the measures of syntax comprehension (TACL-R) and mean length of spontaneous utterances obtained in 12-min narrative tasks (MLU-S), yielding two parameters for each participant's comprehension and production: performance at study start and growth trajectory. Predictor variables were obtained by fitting linear growth curves to each individual's concurrent measures of nonverbal visual cognition (Pattern Analysis subtest of the Stanford-Binet), visual short-term memory (Bead Memory subtest), and auditory short-term memory (digit span), yielding two individual predictor parameters for each measure: performance at study start and growth trajectory. Chronological age at study start (grand-mean centered), sex, and hearing status were also taken as predictors. The best-fitting HLM model of the comprehension parameters uses age at study start, visual short-term memory, and auditory short-term memory as predictors of initial status and age at study start as a predictor of growth trajectory. The model accounted for 90% of the variance in intercept parameters, 79% of the variance in slope parameters, and 24% of the variance at level 1. The same predictors were significant predictors of initial status in the best model for production, with no measures predicting slope. The model accounted for 81% of the intercept variance and 43% of the level 1 variance. When comprehension parameters are added to the predictor set, the best model, accounting for 94% of the intercept and 22% of the slope variance, uses only comprehension at study start as a predictor of initial status and comprehension slope as a predictor of production slope. These results reflect the fact that expressive language acquisition continues in adolescence and is predicted by syntax comprehension and its growth trajectory.
Cultural Differences in Beliefs and Practices Concerning Talk to Children
Authors: Johnston Judith R. , Wong M.-Y. Anita
Published: April 2006

Sporadic observations of non-Western culture groups have made it clear that the large literature on child-directed talk primarily describes Western parent-child interaction patterns. The current study used a survey instrument to contrast the childrearing beliefs and related verbal interaction practices of Chinese and Western mothers of preschoolers. Stepwise regression procedures indicated that culture differences in ratings for 6 belief statements and 5 interaction patterns accounted for 66–67% of the total variance. Discriminate functions derived from the regression analyses identified members of the two culture groups with 94–95% accuracy. The findings call into question the advice commonly given to parents of children with language delay and point to specific areas where practices more harmonious with Chinese culture could be recommended.
Thresholds of Discomfort for Complex Stimuli
Authors: Warner Rebecca L. , Bentler Ruth A.
Published: April 2006

The purpose of this study was to explain differences in threshold of discomfort (TD) across complex stimuli using acoustic and sound-quality variables as predictors. Two 4-tone complexes and 10 environmental sounds were used as stimuli. The environmental sounds consisted of a baby crying, hairdryer blowing, glass breaking, jet engine propelling, person laughing, motorcycle accelerating, orchestra tuning, telephone ringing, siren blowing, and toilet flushing. One-third octave band (1/3 OB) spectra were obtained for the 12 stimuli, with overall rms amplitude held constant across the stimuli. Nine acoustic quantities describing the high- and low-frequency content, peakiness, and bandwidth of each 1/3 OB spectrum were defined. Twenty adult subjects, 6 men and 14 women, with normal hearing sensitivity participated in the study. TDs were obtained from each subject for all of the stimuli. In addition, subjects rated each of the stimuli for annoyance, harshness, loudness, noisiness, and tinniness on a 10-point scale. These ratings were completed at a level 10 dB below each subject's TD for that stimulus. A hierarchical multiple regression analysis was used to estimate the amount of variance in TDs accounted for by subject differences, defined acoustic properties, and sound-quality ratings. Results indicated that, after controlling for intersubject differences, acoustic and sound-quality factors significantly influenced TD ratings. Increases in high-frequency cutoff and low-frequency cutoff, as well as higher ratings of loudness and annoyance, were associated with higher TDs. Associated with lower TDs were an increase in the frequency of the primary spectral peak, an increase in the number of spectral peaks, an increase in the center frequency, an increase in the area under the frequency response curve 30 dB down from the peak amplitude, an increase in the calculated loudness level re ANSI S3.4-1980, and higher ratings of tinniness.
Developmental Change in Variability of Lip Muscle Activity During Speech
Authors: Wohlert Amy B. , Smith Anne
Published: April 2006

Compared to adults, children's speech production measures sometimes show higher trial-to-trial variability in both kinematic and acoustic analyses. A reasonable hypothesis is that this variability reflects variations in neural drive to muscles as the developing system explores different solutions to achieving vocal tract goals. We investigated that hypothesis in the present study by analyzing EMG waveforms produced across repetitions of a phrase spoken by 7-year-olds, 12-year-olds, and young adults. The EMG waveforms recorded via surface electrodes at upper lip sites were clearly modulated in a consistent manner corresponding to lip closure for the bilabial consonants in the utterance. Thus we were able to analyze the amplitude envelope of the rectified EMG with a phrase-level variability index previously used with kinematic data. Both the 7- and 12-year-old children were significantly more variable on repeated productions than the young adults. These results support the idea that children are using varying combinations of muscle activity to achieve phonetic goals. Even at age 12 years, these children were not adult-like in their performance. These and earlier kinematic studies of the oral motor system suggest that children retain their flexibility, employing more degrees of freedom than adults, to dynamically control lip aperture during speech. This strategy is adaptive given the many neurophysiological and biomechanical changes that occur during the transition from adolescence to adulthood.
Direct Magnitude Estimation and Interval Scaling of Naturalness and Severity in Tracheoesophageal (TE) Speakers
Authors: Eadie Tanya L. , Doyle Philip C.
Published: April 2006

The purpose of this study was to determine the psychophysical character and validity of auditory-perceptual ratings of naturalness and overall severity for tracheoesophageal (TE) speech. This was achieved through use of direct magnitude estimation (DME) and equal-appearing interval (EAI) scaling procedures. Twenty adult listeners judged speech naturalness and overall severity from connected speech samples produced by 20 adult male TE speakers. A comparison of DME- and EAI-scaled judgments yielded a metathetic continuum for naturalness and a prothetic continuum for overall severity. These data provide support for the use of either DME or EAI scales in auditory-perceptual ratings of naturalness, but they provide support only for DME scales in judging overall severity for TE speech. The present results suggest that the nature of perceptual phenomena (prothetic vs. metathetic) for TE speakers is consistent with findings for the same dimensions produced by normal laryngeal speakers. These data also support a need for further study of perceptual dimensions associated with TE voice and speech in order to avoid the inappropriate and invalid use of EAI scales frequently found in diagnosis, assessment, and evaluation of this clinical population.
Articulatory Movements in Adolescents
Authors: Walsh Bridget , Smith Anne
Published: April 2006

In order to contribute to a more comprehensive model of speech motor development, we examined the movement trajectories of the upper lip, lower lip, and jaw to determine (a) if there are changes in articulatory motor control in late adolescence; b) if there are sex differences during this developmental period, perhaps related to differences in craniofacial growth rates; (c) if control of jaw motion is adultlike earlier than control of the upper and lower lip; and (d) if control of spatial and temporal aspects of articulatory movement co-develop in adolescence. Participants were 12-, 14-, and 16-year-olds, and young adults (mean age 21.2 years), with 15 males and 15 females per group. A measure reflecting spatiotemporal consistency in trajectory formation for repeated productions of a phrase was calculated for the upper lip, lower lip, and jaw movements. Overall trajectory variability was higher for adolescents compared to young adults. Jaw trajectories were less variable than upper lip or lower lip trajectories, but all effectors showed parallel decreases in variability as age increased, suggesting that control of jaw movement does not reach adult performance before control of the lips. Separate temporal and spatial measures revealed that adolescents had significantly longer movement durations, lower velocities, smaller displacements, and greater variability on these measures than young adults. There were no sex differences on any measure examined, suggesting that peripheral growth factors do not account for this protracted developmental time course. These results provide initial evidence of significant changes in speech motor control processes during adolescence.
Effects of Prelinguistic Milieu Teaching and Parent Responsivity Education on Dyads Involving Children With Intellectual Disabilities
Authors: Yoder Paul J. , Warren Steven F.
Published: April 2006

This study tested the effect of a method of facilitating prelinguistic communication on parents' responsivity and children's communication and productive language development. The method involved Responsivity education for the parents and Prelinguistic Milieu Teaching for the children (RPMT). Thirty-nine prelinguistic toddlers with intellectual disabilities and their primary caregivers participated in this study. Parent-child pairs were randomly assigned to either the RPMT group or a control group. Communication and language were assessed at study entry and 6, 9, and 12 months later. RPMT facilitated parental responsivity in the posttreatment period. The effect of RPMT on growth rate of child-initiated comments (i.e., the most common type of initiating joint attention) varied by pretreatment measures of that variable. The effect of RPMT on growth rate of child-initiated requests (i.e., the most common type of initiating behavior regulation) varied by presence or absence of Down syndrome. Finally, the effect of RPMT on growth of productive language varied by pretreatment frequency of canonical vocal communication. Recommended alterations in PMT and implications for defining which nonspeaking children are appropriate for prelinguistic goals and treatment were discussed.
Spectral Contributions to the Benefit From Spatial Separation of Speech and Noise
Authors: Dubno Judy R. , Ahlstrom Jayne B. , Horwitz Amy R.
Published: April 2006

Speech recognition in noise improves when speech and noise sources are separated in space. This benefit has two components whose effects are strongest in different frequency regions: (1) interaural level differences (e.g., head shadow), which are largest at higher frequencies, and (2) interaural time differences, which have their greatest contribution at lower frequencies. Binaural interactions enhance the separation of signals from noise through the use of these interaural differences. Here, the benefit attributable to spatial separation was measured as a function of the low- and high-pass cutoff frequency of speech and noise. Listeners were younger adults with normal hearing, older adults with normal hearing, and older adults with hearing loss. Binaural thresholds for narrowband noises were measured in quiet and in a speech-shaped masker as a function of masker low-pass cutoff frequency. Speech levels corresponding to 50% correct recognition of sentences from the Hearing in Noise Test (HINT) were measured in a 65-dB SPL speech-shaped noise. Thresholds for narrowband noises and for speech were measured with two loudspeaker configurations: (1) signals and speech-shaped noise at 0° azimuth (in front of the listener) and (2) signals at 0° azimuth and speech-shaped noise at 90° azimuth (at the listener's side). The criterion measure was spatial separation benefit, or the difference in thresholds for the two conditions. Benefit of spatial separation for unfiltered speech averaged 6.1 dB for younger listeners with normal hearing, 4.9 dB for older listeners with normal hearing, and 2.7 dB for older listeners with hearing loss. Benefit was differentially affected by low-pass and high-pass filtering, suggesting a trade-off of the contributions of higher frequency interaural level differences and lower frequency interaural timing cues. As expected, older listeners with hearing loss benefited little from the improved signal-to-noise ratios in the higher frequencies resulting from head shadow, but showed some benefit from lower frequency cues. Spatial benefit for older listeners with normal hearing was reduced relative to benefit for younger listeners. This result may be related to older listeners' elevated thresholds at frequencies above 6.0 kHz.
The Perception of "Sine-Wave Speech" by Adults With Developmental Dyslexia
Authors: Rosner Burton S. , Talcott Joel B. , Witton Caroline , Hogg James D. , Richardson Alexandra J. , Hansen Peter C. , Stein John F.
Published: April 2006

Numerous studies have shown that, as a group, children or adults with developmental dyslexia perceive isolated syllables or words abnormally. Continuous speech containing reduced acoustic information also might prove perceptually difficult to such listeners. They might, however, exploit the intact syntactic and semantic features present in whole utterances, thereby compensating fully for impaired speech perception. "Sine-wave speech" sentences afford a test of these competing possibilities. The sentences contain only 4 frequency-modulated sine waves, lacking many acoustic cues present in natural speech. Adults with and without dyslexia were asked to orally reproduce 9 sine-wave utterances, each occurring in 4 immediately successive trials. Participants with dyslexia reported fewer words than did control listeners. Practice, phonological contrasts, and word position affected both groups similarly. Comprehension of sine-wave sentences seems impaired in many, but not all, adults with dyslexia. A reduced auditory memory capacity may contribute to this deficit.
French-English Bilingual Children With SLI
Authors: Paradis Johanne , Crago Martha , Genesee Fred , Rice Mabel
Published: April 2006

The goal of this study was to determine whether bilingual children with specific language impairment (SLI) are similar to monolingual age mates with SLI, in each language. Eight French-English bilingual children with SLI were compared to agematched monolingual children with SLI, both English and French speaking, with respect to their use of morphosyntax in language production. Specifically, using the extended optional infinitive (EOI) framework, the authors examined the children’s use of tense-bearing and non-tense-bearing morphemes in obligatory context in spontaneous speech. Analyses revealed that the patterns predicted by the EOI framework were borne out for both the monolingual and bilingual children with SLI: The bilingual and monolingual children with SLI showed greater accuracy with non-tense than with tense morphemes. Furthermore, the bilingual and monolingual children with SLI had similar mean accuracy scores for tense morphemes, indicating that the bilingual children did not exhibit more profound deficits in the use of these grammatical morphemes than their monolingual peers. In sum, the bilingual children with SLI in this study appeared similar to their monolingual peers for the aspects of grammatical morphology examined in each language. These bilingual-monolingual similarities point to the possibility that SLI may not be an impediment to learning two languages, at least in the domain of grammatical morphology.
Agrammatic Comprehension of Simple Active Sentences With Moved Constituents
Authors: Friedmann Naama , Shapiro Lewis P.
Published: April 2006

This study examines agrammatic comprehension of object-subject-verb (OSV) and object-verb-subject (OVS) structures in Hebrew. These structures are syntactically identical to the basic order subject-verb-object (SVO) sentence except for the movement of the object to the beginning of the sentence, and thus enable empirical examination of syntactic movement in agrammatic comprehension. Seven individuals with agrammatism, 7 individuals with conduction aphasia, and 7 individuals without language impairment, all native speakers of Hebrew, performed a sentence-picture matching task. The task compared OSV and OVS sentences to SVO sentences and to subject and object relatives. Individuals with agrammatism performed more poorly than those in either of the other groups. Their comprehension of SVO sentences was significantly above chance, but comprehension of OSV and OVS sentences was at chance and was poorer than comprehension of SVO sentences. These results show that agrammatic comprehension of structures that involve movement of a noun phrase is impaired even when the structure is a simple active sentence, in line with the Trace Deletion Hypothesis (TDH; Y. Grodzinsky, 1990, 1995a, 2000). A modification is suggested to accommodate the TDH with the VP Internal Subject Hypothesis, according to which individuals with agrammatism use an "Avoid Movement" strategy in comprehension.
Morphology in Picture Descriptions Provided by Persons With Alzheimer's Disease
Authors: Kavé Gitit , Levy Yonata
Published: April 2006

The language of persons with Alzheimer's disease (AD) has been characterized by semantic-conceptual deterioration versus structural preservation, yet the research has not examined possible differentiation between syntactic and morphological knowledge. Taking advantage of the rich morphology of Hebrew, the current paper looks at these two aspects of grammatical knowledge in descriptions of the Cookie Theft picture. Speech samples were collected from 14 persons with AD and 48 elderly control participants and analyzed for semantic, syntactic, and morphological knowledge or difficulties. Analyses showed that although persons with AD conveyed less information and made more semantic errors than did control participants, their language remained structurally rich. Persons with AD used the same syntactic structures and the same morphological forms as control participants and made very few structural errors.
Perceptual Normalization for Inter- and Intratalker Variation in Cantonese Level Tones
Authors: Wong Patrick C. M. , Diehl Randy L.
Published: April 2006

Inter- and intratalker variation in the production of lexical tones may contribute to acoustic overlap among tone categories. The present study investigated whether such category overlap gives rise to perceptual ambiguity and, if so, whether listeners are able to reduce this ambiguity using contextual information. In the first experiment, native Cantonese-speaking listeners were asked to identify isolated Cantonese level tones produced by 7 talkers. Identification accuracy was significantly higher when the presentation of items was blocked by talker rather mixed across talkers. In the second experiment, listeners identified the final (target) tone of 6-syllable semantically neutral sentences with f
0
patterns of the context (i.e., the first 5 syllables) altered. The same target tone was identified differently depending on the context. In the third experiment, the context portions of stimulus sentences from the second experiment were divided into 2 halves, and their f
0
patterns were altered independently. In identifying the target tone, listeners relied more heavily on the f
0
pattern of the second (last) half of the context. These results are discussed in relation to characteristic inter- and intratalker variations of lexical tones.
Evidence of Motor Programming Deficits in Children Diagnosed With DAS
Authors: Nijland Lian , Maassen Ben , van der Meulen Sjoeke
Published: April 2006

In this study the hypothesis of motor programming involvement in developmental apraxia of speech (DAS) was investigated by studying articulatory compensation. Five children with DAS and 5 normally speaking children (age 5;0 [years;months] to 6;10), and 6 adult women produced utterances in a normal speaking condition and in a bite-block condition in which the mandible was kept in a fixed position. Throughout the utterances, the course of the second formant was used to determine articulatory compensation and the effect of the bite block on anticipatory coarticulation. Results showed that the bite-block condition in normally speaking children, like in adult women, did not affect the extent of anticipatory coarticulation. In the speech of children with DAS, the bite block had large effects on coarticulatory patterns and on vowel quality, which, contrary to expectations, had improved. These results are interpreted as a clear demonstration of deficient motor programming in DAS.
Completion of the Consonant Inventory of Arabic
Authors: Amayreh Mousa M.
Published: April 2006

This study is a follow-up of previous research on the acquisition of Arabic consonants in normally developing children between the ages of 2 and 6 years. The purpose of this study was to provide normative data on the acquisition of late consonants that had not been acquired by the age of 6;4 (years;months). Speech samples from 60 Arabic-speaking children between ages 6;6 and 8;4, in Amman, Jordan, were analyzed to determine the age at which 10 late consonants had been acquired and to determine the error patterns and sound changes used. Five of these consonants had still not been acquired in their standard form (Educated Spoken Arabic) by even the oldest children. However, 8 of the late consonants were produced in their acceptable colloquial forms by age 7;4 and all 10 by age 8;4. The late acquisition of these consonants was discussed from the point of view of functional load and markedness. Implications for diagnosis of articulation disorders and reading problems were considered.
Generalizability Theory I
Authors: O'Brian Nigel , O'Brian Sue , Packman Ann , Onslow Mark
Published: April 2006

Perceptual rating scales can be valid, reliable, and convenient tools for evaluating speech outcomes in research and clinical practice. However, they depend on the perceptions of observers. Too few raters may compromise accuracy, whereas too many would be inefficient. There is therefore a need to determine the minimum number of raters required for a reliable result. In this context, the ideas of Generalizability Theory have become increasingly popular in the behavioral sciences; suggestions have been made for their application to the assessment of speech-language disorders. Here we review the concepts involved, which are applied in a companion article dealing with speech naturalness data obtained from clients who recently completed treatment for their stuttering. We pay particular attention to the statistical requirements of the theory, including some cautions about possible inappropriate use of these techniques. We also offer a new interpretation of the results of the analysis that aims to be more meaningful to most speech-language pathologists.
Articulation Rate and Speech-Sound Normalization Failure
Authors: Flipsen Peter
Published: April 2006

Not all children with speech delay (SD) of unknown origin develop fully normal speech even with intervention. Many retain residual distortion errors into adolescence and ultimately into adulthood. The current study examined whether articulation rate distinguishes those children who retain residual errors from those who normalize. Two groups of speech-delayed children originally identified at preschool age were retested at age 9 years (the early follow-up group) and at age 12–16 years (the late follow-up group), respectively. No differences in articulation rate were observed at either test time in conversational speech between those children who continued to produce residual distortion errors (RE) compared to those children who had fully normalized speech (NSA). For the late follow-up group, children in the RE outcome group articulated speech at significantly slower rates than the children in the NSA outcome group in an embedded words task using both syllables per second and phones per second measures. Findings suggested that children with SD of unknown origin who fail to normalize may have relative speech-motor deficits and possibly deficits in language formulation skill. Alternatively, slower articulation rate in structured tasks may represent some sort of compensation for the continuing presence of speech-sound errors. Possible motivations for such compensation are discussed.
Vowel Category Dependence of the Relationship Between Palate Height, Tongue Height, and Oral Area
Authors: Hasegawa-Johnson Mark , Pizza Shamala , Alwan Abeer , Alwan Jul Setsu , Haker Katherine
Published: April 2006

This article evaluates intertalker variance of oral area, logarithm of the oral area, tongue height, and formant frequencies as a function of vowel category. The data consist of coronal magnetic resonance imaging (MRI) sequences and acoustic recordings of 5 talkers, each producing 11 different vowels. Tongue height (left, right, and midsagittal), palate height, and oral area were measured in 3 coronal sections anterior to the oropharyngeal bend and were subjected to multivariate analysis of variance, variance ratio analysis, and regression analysis. The primary finding of this article is that oral area (between palate and tongue) showed less intertalker variance during production of vowels with an oral place of articulation (palatal and velar vowels) than during production of vowels with a uvular or pharyngeal place of articulation. Although oral area variance is place dependent, percentage variance (log area variance) is not place dependent. Midsagittal tongue height in the molar region was positively correlated with palate height during production of palatal vowels, but not during production of nonpalatal vowels. Taken together, these results suggest that small oral areas are characterized by relatively talker-independent vowel targets and that meeting these talkerindependent targets is important enough that each talker adjusts his or her own tongue height to compensate for talker-dependent differences in constriction anatomy. Computer simulation results are presented to demonstrate that these results may be explained by an acoustic control strategy: When talkers with very different anatomical characteristics try to match talker-independent formant targets, the resulting area variances are minimized near the primary vocal tract constriction.
Collaborative Referencing Between Individuals With Aphasia and Routine Communication Partners
Authors: Hengst Julie A.
Published: April 2006

H. H. Clark (1992) argues that successful referencing depends on speakers and listeners working together to establish shared perspectives on target objects. In his collaborative referencing model, he identifies 3 phases in the referencing process: initiation, refashioning, and acceptance. For referencing tasks, successful collaboration can be seen in the streamlining of referencing expressions and in the decrease of overt collaborative effort across trials. Although previous studies have shown that speakers with aphasia can be successful on referencing tasks, they have not examined how that success is achieved through the collaborative work of the partners. Using a referencing task adapted from H. H. Clark and D. Wilkes-Gibbs (1986), this study examined how 4 adults with moderate-to-severe aphasia collaborated with routine communication partners (spouses or children). Overall, these pairs completed the referencing task trials with 96% accuracy and displayed referencing processes that generally conformed to Clark's collaborative referencing model. Close analysis of the discourse of these interactions revealed patterns of collaboration that went beyond Clark's model—the pairs used diverse verbal and nonverbal resources, actively negotiated the task across trials, and layered their own personal goals and perspectives onto these interactions. This study highlights the plasticity of functional communication (the diversity of ways the pairs worked together to complete the same task) and points to the importance of understanding processes of tacit learning that take place in social interactions.
Grammatical Morpheme Effects on MLU
Authors: Leonard Laurence B. , Finneran Denise
Published: April 2006

Studies of children with specific language impairment (SLI) often include 2 comparison groups of typically developing children—a group matched according to age and a group matched according to mean length of utterance (MLU). In these studies, both groups of typically developing children often perform better than the SLI group. For many of these investigations, grammatical morpheme use constitutes the dependent measure. The use of grammatical morphemes requires longer utterances than the failure to use these morphemes. If children with SLI show less use of grammatical morphemes than typically developing children matched for MLU, shouldn't they produce some other detail of language more frequently than the MLU-matched group¿ In this article, the authors report 2 studies showing that such offsetting effects are not necessary in principle, given the nature of MLU. The implications of these findings are discussed.
Vocal Dose Measures
Authors: Titze Ingo R. , Švec Jan G. , Popolo Peter S.
Published: April 2006

To measure the exposure to self-induced tissue vibration in speech, three vocal doses were defined and described:
distance dose
, which accumulates the distance that tissue particles of the vocal folds travel in an oscillatory trajectory;
energy dissipation dose
, which accumulates the total amount of heat dissipated over a unit volume of vocal fold tissues; and
time dose
, which accumulates the total phonation time. These doses were compared to a previously used vocal dose measure, the
vocal loading index
, which accumulates the number of vibration cycles of the vocal folds. Empirical rules for viscosity and vocal fold deformation were used to calculate all the doses from the fundamental frequency (F
0
) and sound pressure level (SPL) values of speech. Six participants were asked to read in normal, monotone, and exaggerated speech and the doses associated with these vocalizations were calculated. The results showed that large F
0
and SPL variations in speech affected the dose measures, suggesting that accumulation of phonation time alone is insufficient. The vibration exposure of the vocal folds in normal speech was related to the industrial limits for hand-transmitted vibration, in which the safe distance dose was derived to be about 500 m. This limit was found rather low for vocalization; it was related to a comparable time dose of about 17 min of continuous vocalization, or about 35 min of continuous reading with normal breathing and unvoiced segments. The voicing pauses in normal speech and dialogue effectively prolong the safe time dose. The derived safety limits for vocalization will likely require refinement based on a more detailed knowledge of the differences in hand and vocal fold tissue morphology and their response to vibrational stress, and on the effect of recovery of the vocal fold tissue during voicing pauses.
Outcomes of Different Speech and Language Goal Attack Strategies
Authors: Tyler Ann A. , Lewis Kerry E. , Haskill Allison , Tolbert Leslie C.
Published: April 2006

The purpose of this study was to assess phonological and morphosyntactic change in children with co-occurring speech and language impairments using different goal attack strategies. Participants included 47 preschoolers, ages 3;0 (years;months) to 5;11, with impairments in both speech and language: 40 children in the experimental group and 7 in a no-treatment control group. Children in the experimental group were assigned at random to each of 4 different goal attack strategies: (a) in the phonology first condition, children received a 12-week block of phonological intervention followed by 12 weeks of work on morphosyntax; (b) the morphosyntax first condition was the same as phonology first, with the order of interventions reversed; (c) the alternating condition involved intervention on phonology and morphosyntax goals that alternated domains weekly; and (d) the simultaneous condition addressed phonological and morphosyntactic goals each session. Data were collected pretreatment, after the first intervention block, and posttreatment (after 24 weeks). For the control group, data were collected at the beginning and end of a period equivalent to 1 intervention block. Change in a finite morpheme composite and target generalization phoneme composite was assessed. Results showed that morphosyntactic change was greatest for children receiving the alternating strategy after 24 weeks of intervention. No single goal attack strategy was superior in facilitating gains in phonological performance. These results provide preliminary evidence that alternating phonological and morphosyntactic goals may be preferable when children have co-occurring deficits in these domains; further research regarding cross-domain intervention outcomes is necessary.
Deaf Adults Without Attention Deficit Hyperactivity Disorder Display Reduced Perceptual Sensitivity and Elevated Impulsivity on the Test of Variables of Attention (T.O.V.A.)
Authors: Parasnis Ila , Samar Vincent J. , Berent Gerald P.
Published: April 2006

The Test of Variables of Attention (T.O.V.A.; R. A. Leark, T. R. Dupuy, L. M. Greenberg, C. L. Corman, & C. L. Kindeschi, 1996) is a continuous performance test used widely to help diagnose attention deficit hyperactivity disorder (ADHD) in both hearing and deaf people. The T.O.V.A. previously has been normed only on the hearing population. The T.O.V.A. performance of 38 prelingually and severely-to-profoundly deaf young adults and 34 hearing young adults who did not have ADHD was examined in this study. Deaf and hearing participants did not differ on the T.O.V.A. omission variables. However, deaf participants had significantly lower
d
' scores than hearing participants, indicating reduced perceptual sensitivity to the distinction between target and distractor stimuli. Consistent with the existing literature on attentional reorganization in the deaf population, this result was interpreted as indicating a deafness-related reduction in attention to centrally presented stimuli. Deaf participants also showed 2 to 3 times more commission errors than hearing participants and displayed a higher incidence of anticipatory errors. These results suggest a deafness-related increase in impulsivity at the time of response initiation. Beta score analysis confirmed that deaf participants adopted an overall less conservative (more impulsive) response criterion that contributed to their total elevated commission errors. However, a portion of the commission errors was secondary to their reduced
d
', not to increased behavioral impulsivity. Separate factor analyses of the standard T.O.V.A. variables revealed highly similar factor structures for deaf and hearing participants, indicating similar construct validity of the T.O.V.A. for both groups. The evidence for increased inattention and impulsivity in a non-ADHD deaf sample are interpreted in the context of an adaptive attentional reorganization due to deafness. Along with the factor analytic results, these considerations suggest that separate T.O.V.A. norms must be developed for the deaf population to avoid overdiagnosis of ADHD in deaf individuals.