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OBJECTIVES: Understanding how quantity and quality of language input vary across children with cochlear implants (CIs) is important for explaining sources of large individual differences in language outcomes of this at-risk pediatric population. Studies have mostly focused either on intervention-related, device-related, and/or patient-related factors, or relied on data from parental reports and laboratory-based speech corpus to unravel factors explaining individual differences in language outcomes among children with CIs. However, little is known about the extent to which children with CIs differ in quantity and quality of language input they experience in their natural linguistic environments. To address this knowledge gap, the present study analyzed the quantity and quality of language input to early-implanted children (age of implantation <23 mo) during the first year after implantation. DESIGN: Day-long Language ENvironment Analysis (LENA) recordings, derived from home environments of 14 early-implanted children, were analyzed to estimate numbers of words per day, type-token ratio (TTR), and mean length of utterance in morphemes (MLUm) in adults' speech. Properties of language input were analyzed across these three dimensions to examine how input in home environments varied across children with CIs in quantity, defined as number of words, and quality, defined as whether speech was child-directed or overheard. RESULTS: Our per-day estimates demonstrated that children with CIs were highly variable in the number of total words (mean ± SD = 25,134 ± 9,267 words) and high-quality child-directed words (mean ± SD = 10,817 ± 7,187 words) they experienced in a day in their home environments during the first year after implantation. The results also showed that the patterns of variability across children in quantity and quality of language input changes depending on whether the speech was child-directed or overheard. Children also experienced highly different environments in terms of lexical diversity (as measured by TTR) and morphosyntactic complexity (as measured by MLUm) of language input. The results demonstrated that children with CIs varied substantially in the quantity and quality of language input experienced in their home environments. More importantly, individual children experienced highly variable amounts of high-quality, child-directed speech, which may drive variability in language outcomes across children with CIs. CONCLUSIONS: Analyzing early language input in natural, linguistic environments of children with CIs showed that the quantity and quality of early linguistic input vary substantially across individual children with CIs. This substantial individual variability suggests that the quantity and quality of early linguistic input are potential sources of individual differences in outcomes of children with CIs and warrant further investigation to determine the effects of this variability on outcomes.
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Implantación Coclear , Implantes Cocleares , Sordera , Percepción del Habla , Adulto , Niño , Humanos , Desarrollo del Lenguaje , Lingüística , HablaRESUMEN
OBJECTIVES: Early home auditory environment plays an important role in children's spoken language development and overall well-being. This study explored differences in the home auditory environment experienced by children with cochlear implants (CIs) relative to children with normal hearing (NH). DESIGN: Measures of the child's home auditory environment, including adult word count (AWC), conversational turns (CTs), child vocalizations (CVs), television and media (TVN), overlapping sound (OLN), and noise (NON), were gathered using the Language Environment Analysis System. The study included 16 children with CIs (M = 22.06 mo) and 25 children with NH (M = 18.71 mo). Families contributed 1 to 3 daylong recordings quarterly over the course of approximately 1 year. Additional parent and infant characteristics including maternal education, amount of residual hearing, and age at activation were also collected. RESULTS: The results showed that whereas CTs and CVs increased with child age for children with NH, they did not change as a function of age for children with CIs; NON was significantly higher for the NH group. No significant group differences were found for the measures of AWC, TVN, or OLN. Moreover, measures of CTs, CVs, TVN, and NON from children with CIs were associated with demographic and child factors, including maternal education, age at CI activation, and amount of residual hearing. CONCLUSIONS: These findings suggest that there are similarities and differences in the home auditory environment experienced by children with CIs and children with NH. These findings have implications for early intervention programs to promote spoken language development for children with CIs.
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Implantación Coclear , Implantes Cocleares , Sordera , Adulto , Niño , Audición , Pruebas Auditivas , Humanos , Lactante , Desarrollo del LenguajeRESUMEN
Automatic speech processing devices have become popular for quantifying amounts of ambient language input to children in their home environments. We assessed error rates for language input estimates for the Language ENvironment Analysis (LENA) audio processing system, asking whether error rates differed as a function of adult talkers' gender and whether they were speaking to children or adults. Audio was sampled from within LENA recordings from 23 families with children aged 4-34 months. Human coders identified vocalizations by adults and children, counted intelligible words, and determined whether adults' speech was addressed to children or adults. LENA's classification accuracy was assessed by parceling audio into 100-ms frames and comparing, for each frame, human and LENA classifications. LENA correctly classified adult speech 67% of the time across families (average false negative rate: 33%). LENA's adult word count showed a mean +47% error relative to human counts. Classification and Adult Word Count error rates were significantly affected by talkers' gender and whether speech was addressed to a child or an adult. The largest systematic errors occurred when adult females addressed children. Results show LENA's classifications and Adult Word Count entailed random - and sometimes large - errors across recordings, as well as systematic errors as a function of talker gender and addressee. Due to systematic and sometimes high error in estimates of amount of adult language input, relying on this metric alone may lead to invalid clinical and/or research conclusions. Further validation studies and circumspect usage of LENA are warranted.
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Lenguaje , Habla , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Adulto JovenRESUMEN
The importance of secondary-stressed (SS) and unstressed-unreduced (UU) syllable accuracy for spoken word recognition in English is as yet unclear. An acoustic study first investigated Russian learners' of English production of SS and UU syllables. Significant vowel quality and duration reductions in Russian-spoken SS and UU vowels were found, likely due to a transfer of native phonological features. Next, a cross-modal phonological priming technique combined with a lexical decision task assessed the effect of inaccurate SS and UU syllable productions on native American English listeners' speech processing. Inaccurate UU vowels led to significant inhibition of lexical access, while reduced SS vowels revealed less interference. The results have implications for understanding the role of SS and UU syllables for word recognition and English pronunciation instruction.
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Multilingüismo , Psicolingüística , Inteligibilidad del Habla/fisiología , Percepción del Habla/fisiología , Adulto , Femenino , Humanos , Masculino , Ohio , Federación de Rusia , Adulto JovenRESUMEN
Humans unconsciously track a wide array of distributional characteristics in their sensory environment. Recent research in spoken-language processing has demonstrated that the speech rate surrounding a target region within an utterance influences which words, and how many words, listeners hear later in that utterance. On the basis of hypotheses that listeners track timing information in speech over long timescales, we investigated the possibility that the perception of words is sensitive to speech rate over such a timescale (e.g., an extended conversation). Results demonstrated that listeners tracked variation in the overall pace of speech over an extended duration (analogous to that of a conversation that listeners might have outside the lab) and that this global speech rate influenced which words listeners reported hearing. The effects of speech rate became stronger over time. Our findings are consistent with the hypothesis that neural entrainment by speech occurs on multiple timescales, some lasting more than an hour.
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Reconocimiento en Psicología/fisiología , Percepción del Habla/fisiología , Habla/fisiología , Adulto , Humanos , Tiempo , Adulto JovenRESUMEN
BACKGROUND: Older adults living in long term care (LTC) settings are vulnerable to fall-related injuries. There is a need to develop and implement evidence-based approaches to address fall injury prevention in LTC. Knowledge translation (KT) interventions to support the uptake of evidence-based approaches to fall injury prevention in LTC need to be responsive to the learning needs of LTC staff and use mediums, such as videos, that are accessible and easy-to-use. This article describes the development of two unique educational videos to promote fall injury prevention in long-term care (LTC) settings. These videos are unique from other fall prevention videos in that they include video footage of real life falls captured in the LTC setting. METHODS: Two educational videos were developed (2012-2013) to support the uptake of findings from a study exploring the causes of falls based on video footage captured in LTC facilities. The videos were developed by: (1) conducting learning needs assessment in LTC settings via six focus groups (2) liaising with LTC settings to identify learning priorities through unstructured conversations; and (3) aligning the content with principles of adult learning theory. RESULTS: The videos included footage of falls, interviews with older adults and fall injury prevention experts. The videos present evidence-based fall injury prevention recommendations aligned to the needs of LTC staff and: (1) highlight recommendations deemed by LTC staff as most urgent (learner-centered learning); (2) highlight negative impacts of falls on older adults (encourage meaning-making); and, (3) prompt LTC staff to reflect on fall injury prevention practices (encourage critical reflection). CONCLUSIONS: Educational videos are an important tool available to researchers seeking to translate evidence-based recommendations into LTC settings. Additional research is needed to determine their impact on practice.
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Accidentes por Caídas/prevención & control , Educación Profesional/métodos , Hogares para Ancianos , Cuidados a Largo Plazo/métodos , Heridas y Lesiones/prevención & control , Anciano , Humanos , Evaluación de Necesidades , Grupo de Atención al Paciente , Grabación en VideoRESUMEN
Pronunciation variation is under-studied in infant-directed speech, particularly for consonants. Regressive place assimilation involves a word-final alveolar stop taking the place of articulation of a following word-initial consonant. We investigated pronunciation variation in word-final alveolar stop consonants in storybooks read by forty-eight mothers in adult-directed or infant-directed style to infants aged approximately 0;3, 0;9, 1;1, or 1;8. We focused on phonological environments where regressive place assimilation could occur, i.e., when the stop preceded a word-initial labial or velar consonant. Spectrogram, waveform, and perceptual evidence was used to classify tokens into four pronunciation categories: canonical, assimilated, glottalized, or deleted. Results showed a reliable tendency for canonical variants to occur in infant-directed speech more often than in adult-directed speech. However, the otherwise very similar distributions of variants across addressee and age group suggested that infants largely experience statistical distributions of non-canonical consonantal pronunciation variants that mirror those experienced by adults.
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Fonética , Acústica del Lenguaje , Adulto , Factores de Edad , Femenino , Humanos , Lactante , Masculino , Relaciones Madre-Hijo , Medición de la Producción del HablaRESUMEN
CONTEXT: Intersecting social determinants of health constrain access to care and treatment adherence among homeless populations. Because clinicians seldom receive training in the social determinants of health, they may be unprepared to account for or address these factors when developing treatment strategies for homeless individuals. OBJECTIVES: This study explored: (i) clinicians' preparedness to provide care responsive to the social determinants of health in homeless populations, and (ii) the steps taken by clinicians to overcome shortcomings in their clinical training in regard to the social determinants of health. METHODS: Qualitative interviews were conducted with doctors (n = 6) and nurses (n = 18) in six Canadian cities. Participants had at least 2 years of experience in providing care to homeless populations. Interview transcripts were analysed using methods of constant comparison. RESULTS: Participants highlighted how, when first providing care to this population, they were unprepared to account for or address social determinants shaping the health of homeless persons. However, participants recognised the necessity of addressing these factors to situate care within the social and structural contexts of homelessness. Participants' accounts illustrated that experiential learning was critical to increasing capacity to provide care responsive to the social determinants of health. Experiential learning was a continuous process that involved: (i) engaging with homeless persons in multiple settings and contexts to inform treatment strategies; (ii) evaluating the efficacy of treatment strategies through continued observation and critical reflection, and (iii) adjusting clinical practice to reflect observations and new knowledge. CONCLUSIONS: This study underscores the need for greater emphasis on the social determinants of health in medical education in the context of homelessness. These insights may help to inform the development and design of service-learning initiatives that integrate understandings of the social determinants of health, and thus potentially improve the readiness of clinicians to address the complex factors that shape the health of homeless populations.
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Accesibilidad a los Servicios de Salud , Personas con Mala Vivienda , Actitud del Personal de Salud , Canadá , Competencia Clínica/normas , Personal de Salud/educación , Disparidades en el Estado de Salud , Humanos , Aprendizaje Basado en Problemas , Práctica Profesional , Relaciones Profesional-Paciente , Autoeficacia , Encuestas y CuestionariosRESUMEN
Rhythm perception deficits have been linked to neurodevelopmental disorders affecting speech and language. Children who stutter have shown poorer rhythm discrimination and attenuated functional connectivity in rhythm-related brain areas, which may negatively impact timing control required for speech. It is unclear whether adults who stutter (AWS), who are likely to have acquired compensatory adaptations in response to rhythm processing/timing deficits, are similarly affected. We compared rhythm discrimination in AWS and controls (total n = 36) during fMRI in two matched conditions: simple rhythms that consistently reinforced a periodic beat, and complex rhythms that did not (requiring greater reliance on internal timing). Consistent with an internal beat deficit hypothesis, behavioral results showed poorer complex rhythm discrimination for AWS than controls. In AWS, greater stuttering severity was associated with poorer rhythm discrimination. AWS showed increased activity within beat-based timing regions and increased functional connectivity between putamen and cerebellum (supporting interval-based timing) for simple rhythms.
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Tartamudeo , Niño , Humanos , Adulto , Tartamudeo/diagnóstico por imagen , Imagen por Resonancia Magnética , Percepción Auditiva/fisiología , Habla/fisiología , Encéfalo/diagnóstico por imagenRESUMEN
In this paper, we will attempt to outline the key ideas of a theoretical framework for neuroscience research that reflects critically on the neoliberal capitalist context. We argue that neuroscience can and should illuminate the effects of neoliberal capitalism on the brains and minds of the population living under such socioeconomic systems. Firstly, we review the available empirical research indicating that the socio-economic environment is harmful to minds and brains. We, then, describe the effects of the capitalist context on neuroscience itself by presenting how it has been influenced historically. In order to set out a theoretical framework that can generate neuroscientific hypotheses with regards to the effects of the capitalist context on brains and minds, we suggest a categorization of the effects, namely deprivation, isolation and intersectional effects. We also argue in favor of a neurodiversity perspective [as opposed to the dominant model of conceptualizing neural (mal-)functioning] and for a perspective that takes into account brain plasticity and potential for change and adaptation. Lastly, we discuss the specific needs for future research as well as a frame for post-capitalist research.
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BACKGROUND: Homeless and marginally housed persons who use alcohol and/or illicit drugs often have end-of-life care needs that go unmet due to barriers that they face to accessing end-of-life care services. Many homeless and marginally housed persons who use these substances must therefore rely upon alternate sources of end-of-life care and support. This article explores the role of harm reduction services in end-of-life care services delivery to homeless and marginally housed persons who use alcohol and/or illicit drugs. METHODS: A qualitative case study design was used to explore end-of-life care services delivery to homeless and marginally housed persons in six Canadian cities. A key objective was to explore the role of harm reduction services. 54 health and social services professionals participated in semi-structured qualitative interviews. All participants reported that they provided care and support to this population at end-of-life. RESULTS: Harm reduction services (e.g., syringe exchange programs, managed alcohol programs, etc.) were identified as a critical point-of-entry to and source of end-of-life care and support for homeless and marginally housed persons who use alcohol and/or illicit drugs. Where possible, harm reduction services facilitated referrals to end-of-life care services for this population. Harm reduction services also provided end-of-life care and support when members of this population were unable or unwilling to access end-of-life care services, thereby improving quality-of-life and increasing self-determination regarding place-of-death. CONCLUSIONS: While partnerships between harm reduction programs and end-of-life care services are identified as one way to improve access, it is noted that more comprehensive harm reduction services might be needed in end-of-life care settings if they are to engage this underserved population.
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Actitud del Personal de Salud , Reducción del Daño , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Personas con Mala Vivienda/estadística & datos numéricos , Relaciones Profesional-Paciente , Trastornos Relacionados con Sustancias/epidemiología , Cuidado Terminal/estadística & datos numéricos , Consumo de Bebidas Alcohólicas/epidemiología , Consumo de Bebidas Alcohólicas/prevención & control , Canadá , Femenino , Humanos , Drogas Ilícitas , Entrevistas como Asunto , Masculino , Evaluación de Programas y Proyectos de Salud , Proyectos de Investigación , Características de la Residencia , Gestión de Riesgos , Índice de Severidad de la Enfermedad , Apoyo Social , Abuso de Sustancias por Vía Intravenosa/epidemiología , Abuso de Sustancias por Vía Intravenosa/prevención & control , Trastornos Relacionados con Sustancias/prevención & controlRESUMEN
BACKGROUND: Homeless populations have complex and diverse end-of-life care needs. However, they typically die outside of the end-of-life care system. To date, few studies have explored barriers to the end-of-life care system for homeless populations. This qualitative study involving health and social services professionals from across Canada sought to identify barriers to the end-of-life care system for homeless populations and generate recommendations to improve their access to end-of-life care. METHODS: Semi-structured qualitative interviews were conducted with 54 health and social services professionals involved in end-of-life care services delivery to homeless persons in six Canadian cities (Halifax, Hamilton, Ottawa, Thunder Bay, Toronto and Winnipeg). Participants included health administrators, physicians, nurses, social workers, harm reduction specialists, and outreach workers. Interviews were audio-recorded, transcribed verbatim and analysed thematically. RESULTS: Participants identified key barriers to end-of-life care services for homeless persons, including: (1) insufficient availability of end-of-life care services; (2) exclusionary operating procedures; and, (3) poor continuity of care. Participants identified recommendations that they felt had the potential to minimize these barriers, including: (1) adopting low-threshold strategies (e.g. flexible behavioural policies and harm reduction strategies); (2) linking with population-specific health and social care providers (e.g. emergency shelters); and, (3) strengthening population-specific training. CONCLUSIONS: Homeless persons may be underserved by the end-of-life care system as a result of barriers that they face to accessing end-of-life care services. Changes in the rules and regulations that reflect the health needs and circumstances of homeless persons and measures to improve continuity of care have the potential to increase equity in the end-of-life care system for this underserved population.
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Recent studies have demonstrated that mothers exaggerate phonetic properties of infant-directed (ID) speech. However, these studies focused on a single acoustic dimension (frequency), whereas speech sounds are composed of multiple acoustic cues. Moreover, little is known about how mothers adjust phonetic properties of speech to children with hearing loss. This study examined mothers' production of frequency and duration cues to the American English tense/lax vowel contrast in speech to profoundly deaf (N = 14) and normal-hearing (N = 14) infants, and to an adult experimenter. First and second formant frequencies and vowel duration of tense (/i/, /u/) and lax (/I/, /Ê/) vowels were measured. Results demonstrated that for both infant groups mothers hyperarticulated the acoustic vowel space and increased vowel duration in ID speech relative to adult-directed speech. Mean F2 values were decreased for the /u/ vowel and increased for the /I/ vowel, and vowel duration was longer for the /i/, /u/, and /I/ vowels in ID speech. However, neither acoustic cue differed in speech to hearing-impaired or normal-hearing infants. These results suggest that both formant frequencies and vowel duration that differentiate American English tense/lx vowel contrasts are modified in ID speech regardless of the hearing status of the addressee.
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Sordera/psicología , Relaciones Madre-Hijo , Madres/psicología , Acústica del Lenguaje , Percepción del Habla , Calidad de la Voz , Estimulación Acústica , Adulto , Audiometría de Tonos Puros , Umbral Auditivo , Estudios de Casos y Controles , Señales (Psicología) , Sordera/diagnóstico , Sordera/fisiopatología , Femenino , Humanos , Lactante , Masculino , Fonética , Índice de Severidad de la Enfermedad , Espectrografía del Sonido , Medición de la Producción del Habla , Factores de TiempoRESUMEN
PURPOSE: This study used a cross-sequential design to identify developmental changes in narrative speech rhythm and intonation. The aim was to provide a robust, clinically relevant characterization of normative changes in speech prosody across the early school-age years. METHOD: Structured spontaneous narratives were elicited annually from 60 children over a 3-year period. Children were aged 5-7 years at study outset and then were aged 7-9 years at study offset. Articulation rate, prominence spacing, and intonational phrase length and duration were calculated for each narrative to index speech rhythm; measures of pitch variability and pitch range indexed intonation. Linear mixed-effects (LME) models tested for cohort-based and within-subject longitudinal change on the prosodic measures; linear regression was used to test for the simple effect of age-in-months within year on the measures. RESULTS: The LME analyses indicated systematic longitudinal changes in speech rhythm across all measures except phrase duration; there were no longitudinal changes in pitch variability or pitch range across the school-age years. Linear regression results showed an increase in articulation rate with age; there were no systematic differences between age cohorts across years in the study. CONCLUSIONS: The results indicate that speech rhythm continues to develop during the school-age years. The results also underscore the very strong relationship between the rate and rhythm characteristics of speech and so suggest an important influence of speech motor skills on rhythm production. Finally, the results on pitch variability and pitch range are interpreted to suggest that these are inadequate measures of typical intonation development during the school-age years.
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Percepción del Habla , Habla , Niño , HumanosRESUMEN
Caregivers modify their speech when talking to infants, a specific type of speech known as infant-directed speech (IDS). This speaking style facilitates language learning compared to adult-directed speech (ADS) in infants with normal hearing (NH). While infants with NH and those with cochlear implants (CIs) prefer listening to IDS over ADS, it is yet unknown how CI processing may affect the acoustic distinctiveness between ADS and IDS, as well as the degree of intelligibility of these. This study analyzed speech of seven female adult talkers to model the effects of simulated CI processing on (1) acoustic distinctiveness between ADS and IDS, (2) estimates of intelligibility of caregivers' speech in ADS and IDS, and (3) individual differences in caregivers' ADS-to-IDS modification and estimated speech intelligibility. Results suggest that CI processing is substantially detrimental to the acoustic distinctiveness between ADS and IDS, as well as to the intelligibility benefit derived from ADS-to-IDS modifications. Moreover, the observed variability across individual talkers in acoustic implementation of ADS-to-IDS modification and the estimated speech intelligibility was significantly reduced due to CI processing. The findings are discussed in the context of the link between IDS and language learning in infants with CIs.
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Implantes Cocleares , Percepción del Habla , Adulto , Percepción Auditiva , Femenino , Humanos , Lactante , Desarrollo del Lenguaje , HablaRESUMEN
A classic problem in spoken language comprehension is how listeners perceive speech as being composed of discrete words, given the variable time-course of information in continuous signals. We propose a syllable inference account of spoken word recognition and segmentation, according to which alternative hierarchical models of syllables, words, and phonemes are dynamically posited, which are expected to maximally predict incoming sensory input. Generative models are combined with current estimates of context speech rate drawn from neural oscillatory dynamics, which are sensitive to amplitude rises. Over time, models which result in local minima in error between predicted and recently experienced signals give rise to perceptions of hearing words. Three experiments using the visual world eye-tracking paradigm with a picture-selection task tested hypotheses motivated by this framework. Materials were sentences that were acoustically ambiguous in numbers of syllables, words, and phonemes they contained (cf. English plural constructions, such as "saw (a) raccoon(s) swimming," which have two loci of grammatical information). Time-compressing, or expanding, speech materials permitted determination of how temporal information at, or in the context of, each locus affected looks to, and selection of, pictures with a singular or plural referent (e.g., one or more than one raccoon). Supporting our account, listeners probabilistically interpreted identical chunks of speech as consistent with a singular or plural referent to a degree that was based on the chunk's gradient rate in relation to its context. We interpret these results as evidence that arriving temporal information, judged in relation to language model predictions generated from context speech rate evaluated on a continuous scale, informs inferences about syllables, thereby giving rise to perceptual experiences of understanding spoken language as words separated in time.
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Comprensión , Habla , Humanos , Memoria , Percepción del Habla , Factores de TiempoRESUMEN
Speech is produced over time, and this makes sensitivity to timing between speech events crucial for understanding language. Two experiments investigated whether perception of function words (e.g., or, are) is rate dependent in casual speech, which often contains phonetic segments that are spectrally quite reduced. In Experiment 1, talkers spoke sentences containing a target function word; slowing talkers' speech rate around this word caused listeners to perceive sentences as lacking the word (e.g., leisure or time was perceived as leisure time). In Experiment 2, talkers spoke matched sentences lacking a function word; speeding talkers' speech rate around the region in which the function word had been embedded in Experiment 1 caused listeners to perceive a function word that was never spoken (e.g., leisure time was perceived as leisure or time). The results suggest that listeners formed expectancies based on speech rate, and these expectancies influenced the number of words and word boundaries perceived. These findings may help explain the robustness of speech recognition when speech signals are distorted (e.g., because of a casual speaking style).
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Atención , Comprensión , Enmascaramiento Perceptual , Semántica , Acústica del Lenguaje , Percepción del Habla , Conducta Verbal , Femenino , Humanos , Masculino , Espectrografía del Sonido , Adulto JovenRESUMEN
The importance of pitch range variation for intonational meaning and theory is well known; however, whether pitch range is a phonetic dimension which is treated categorically in English remains unclear. To test this possibility, three intonation continua varying in pitch range were constructed which had endpoints with contrastive representations under autosegmental-metrical (AM) theory: H* vs. L+H*, H* with 'peak delay' vs. L*+H, and %H L* vs. L*. The prediction derived from AM theory was that the reproduction of continuous pitch range variation should show a discrete pattern reflecting a change in the phonological representation of tonal sequences and in the number of tonal targets across each continuum. Participants' reproductions of each stimulus set showed continuous variation in pitch range, suggesting that pitch range is a gradient phonetic dimension in English conveying semantic contrast, similar to the formant space for vowels. Moreover, the gradience observed in productions across all parts of the pitch range suggests that contours within each series had the same number of tonal targets. The results support a version of AM theory in which rises and falls are usually comprised of two tonal targets, with strictly monotonic f(0) interpolation between them.
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Fonética , Percepción de la Altura Tonal , Espectrografía del Sonido , Acústica del Lenguaje , Adolescente , Femenino , Humanos , Conducta Imitativa , Masculino , Adulto JovenRESUMEN
Early language environment plays a critical role in child language development. The Language ENvironment Analysis (LENA™) system allows researchers and clinicians to collect daylong recordings and obtain automated measures to characterize a child's language environment. This meta-analysis evaluates the predictability of LENA's automated measures for language skills in young children. We systematically searched reports for associations between LENA's automated measures, specifically, adult word count (AWC), conversational turn count (CTC), and child vocalization count (CVC), and language skills in children younger than 48 months. Using robust variance estimation, we calculated weighted mean effect sizes and conducted moderator analyses exploring the factors that might affect this relationship. The results revealed an overall medium effect size for the correlation between LENA's automated measures and language skills. This relationship was largely consistent regardless of child developmental status, publication status, language assessment modality and method, or the age at which the LENA recording was taken; however, the effect was weakly moderated by the gap between LENA recordings and language measures taken. Among the three measures, there were medium associations between CTC and CVC and language, whereas there was a small-to-medium association between AWC and language. These findings extend beyond validation work conducted by the LENA Research Foundation and suggest certain predictive strength of LENA's automated measures for child language. We discussed possible mechanisms underlying the observed associations, as well as the theoretical, methodological, and clinical implications of these findings.
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Purpose Differences across language environments of prelingually deaf children who receive cochlear implants (CIs) may affect language acquisition; yet, whether mothers show individual differences in how they modify infant-directed (ID) compared with adult-directed (AD) speech has seldom been studied. This study assessed individual differences in how mothers realized speech modifications in ID register and whether these predicted differences in language outcomes for children with CIs. Method Participants were 36 dyads of mothers and their children aged 0;8-2;5 (years;months) at the time of CI implantation. Mothers' spontaneous speech was recorded in a lab setting in ID or AD conditions before ~15 months postimplantation. Mothers' speech samples were characterized for acoustic-phonetic and lexical properties established as canonical indices of ID speech to typically hearing infants, such as vowel space area differences, fundamental frequency variability, and speech rate. Children with CIs completed longitudinal administrations of one or more standardized language assessment instruments at variable intervals from 6 months to 9.5 years postimplantation. Standardized scores on assessments administered longitudinally were used to calculate linear regressions, which gave rise to predicted language scores for children at 2 years postimplantation and language growth over 2-year intervals. Results Mothers showed individual differences in how they modified speech in ID versus AD registers. Crucially, these individual differences significantly predicted differences in estimated language outcomes at 2 years postimplantation in children with CIs. Maternal speech variation in lexical quantity and vowel space area differences across ID and AD registers most frequently predicted estimates of language attainment in children with CIs, whereas prosodic differences played a minor role. Conclusion Results support that caregiver language behaviors play a substantial role in explaining variability in language attainment in children receiving CIs. Supplemental Material https://doi.org/10.23641/asha.12560147.