A corpus of consonant-vowel-consonant real words and nonwords: comparison of phonotactic probability, neighborhood density, and consonant age of acquisition

Learning Verbs in Sentences: Children With Developmental Language Disorder and the Role of Retrieval Practice

PURPOSE

Retrieval practice has been shown to assist the word learning of children with developmental language disorder (DLD). Although this has been true for learning new verbs as well as new nouns and adjectives, these children's overall verb learning has remained quite low. In this preregistered study, we presented novel verbs in transitive sentences with varying subjects/agents and objects/patients to determine if recall could be improved and if retrieval practice continued to be facilitative.

METHOD

Fourteen children with DLD aged 4-5 years and 13 same-age peers with typical language development (TD) learned eight novel verbs over two sessions. Half of the novel verbs were presented with spacing between study and retrieval trials, and half were presented with the same frequency in study trials without the opportunity for retrieval. All novel verbs were presented in sentences such as, "The woman is deeking the shoe." Children's ability to recall and use the novel verbs in the same sentence structure was tested after the second session and 1 week later. The children were also required to use the novel verbs in bare-stem form in a new structure, as in, "That woman likes to deek the towel."

RESULTS

Both groups of children showed increased recall relative to a previous novel verb study. The children with TD showed the expected advantages of spaced retrieval over repeated study and could use the novel verbs in the new morphological form and sentence structure. The children with DLD, however, showed an advantage for spaced retrieval only shortly after the learning period. These children had great difficulty changing the novel verbs to a bare stem and using them in a new structure.

CONCLUSION

Although spaced retrieval assists children's novel verb recall, children with DLD in particular require additional help using these verbs with morphological and syntactic flexibility.

Retrieval Practice and Word Learning by Children With Developmental Language Disorder: Does Expanding Retrieval Provide Additional Benefit?

PURPOSE

The word learning of preschool-age children with developmental language disorder (DLD) is improved when spaced retrieval practice is incorporated into the learning sessions. In this preregistered study, we compared two types of spacing-an expanding retrieval practice schedule and an equally spaced schedule-to determine if one of these approaches yields better word learning outcomes for the children.

METHOD

Fourteen children with DLD aged 4-5 years and 14 same-age children with typical language development (TD) learned eight novel nouns over two sessions. Spacing for half of the novel words was expanded gradually during learning; for the remaining novel words, greater spacing remained at the same level throughout learning. Immediately after the second session and 1 week later, the children's recall of the words was tested.

RESULTS

The children with TD recalled more novel words than the children with DLD, although this difference could be accounted for by differences in the children's standardized receptive vocabulary test scores. The two groups were similar in their ability to retain the words over 1 week. Initially, the shorter spacing in the expanding schedule resulted in greater retrieval success than the corresponding (longer spaced) retrieval trials in the equally spaced schedule. These early shorter spaced trials also seemed to benefit retrieval of the trials with greater spacing that immediately followed. However, as the learning period progressed, the accuracy levels for the two conditions converged and were likewise similar during final testing.

CONCLUSION

We need a greater understanding of how and when short spacing can be helpful to children's word learning, with the recognition that early gains might give a misleading picture of the benefits that short spacing can provide to longer term retention.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.25537696.

I remembered the chorm! Word learning abilities of children with and without phonological impairment

BACKGROUND

Children with phonological impairment present with pattern-based errors in their speech production. While some children have difficulties with speech perception and/or the establishment of robust underlying phonological representations, the nature of phonological impairment in children is still not well understood. Given that phonological and lexical development are closely linked, one way to better understand the nature of the problem in phonological impairment is to examine word learning abilities in children.

AIMS

To examine word learning and its relationship with speech perception, speech production and vocabulary knowledge in children aged 4-5 years. There were two variables of interest: speech production abilities ranging from phonological impairment to typical speech; and vocabulary abilities ranging from typical to above average ('lexically precocious').

METHODS & PROCEDURES

Participants were 49 Australian-English-speaking children aged 48-69 months. Children were each taught four novel non-words (out of a selection of eight) through stories, and word learning was assessed at 1 week post-initial exposure. Word learning was assessed using two measures: confrontation naming and story retell naming. Data were analysed by group using independent-samples t-tests and Mann-Whitney U-tests, and continuously using multiple linear regression.

OUTCOMES & RESULTS

There was no significant difference in word learning ability of children with and without phonological impairment, but regardless of speech group, children with above average vocabulary had significantly better word learning abilities than children with average vocabulary. In multiple linear regression, vocabulary was the only significant predictor of variance in word learning ability.

CONCLUSIONS & IMPLICATIONS

Children with phonological impairment can be lexically precocious and learn new words like their peers without phonological impairment. Contrary to expectations, vocabulary knowledge rather than expressive phonological ability explained variance in measures of word learning. These findings question an assumption that children with phonological impairment have underspecified phonological representations. They also highlight the heterogeneity among children with phonological impairment and the need to better understand the nature of their difficulty learning the phonological system of the ambient language.

WHAT THIS PAPER ADDS

What is already known on the subject There is limited research examining the word learning abilities of children with phonological impairment. Most previous research focuses on word properties such as phonotactic probability and neighbourhood density. Within the existing literature there are different reports and conclusions regarding the word learning abilities of children with phonological impairment and whether their word learning differs from that of children with typically developing speech. What this study adds to existing knowledge This study found that vocabulary was the strongest predictor of word learning across children with and without phonological impairment. There was no significant difference in word learning ability between children with and without phonological impairment. However, children with lexically precocious vocabulary abilities were significantly better at word learning than children with average vocabulary abilities. What are the potential or actual clinical implications of this work? Findings from this study support the importance of assessing and considering measures of word learning-including vocabulary-when working with children with phonological impairment. This study indicates that it is possible to use stories coupled with measures of confrontation naming and story retell to gain deeper insight into children's word learning abilities.

Effects of Integrating Different Types of Physical Activity into Virtual Rapid Word Learning Instruction for Children who are Deaf and Hard of Hearing

The purpose of this study was to compare three intervention conditions in virtual rapid word learning instruction for young children who are deaf and hard of hearing (DHH): traditional, general physical activity, and semantic richness physical activity. We focused on an initial step in learning a new word: mapping a word form to a referent. Fourteen children who are DHH and 14 children with typical hearing (TH) participated in a pseudoword-learning virtual session in each condition, and receptive and expressive knowledge of targeted pseudowords was assessed. Of interest was the impact of different types of physical activity on rapid learning of word-like forms. There was an interaction of group and condition for expressive production of pseudowords. Children who were DHH learned to produce more pseudowords in the general physical activity condition, whereas children with TH learned to produce more pseudowords in the semantic richness physical activity condition. There were no effects of group or condition on receptive learning of pseudowords. Children who are DHH can rapidly map word-like forms to referents via teleintervention, and physical activity may interact with word learning differently for children who are DHH and children with TH.

Phonemic Feature Scoring as a Tool for Progress Monitoring During Language Interventions for Children With Autism and Minimal Verbal Skills

PURPOSE

An increasing number of studies focus on verbal treatments for children with autism and minimal verbal skills. However, clinical tools for progress monitoring during interventions are lacking. The aim of this clinical focus article is to provide illustrations on the utility of a phonemic feature scoring system as a progress-monitoring tool, focusing on benefits and limitations as well as indications for use.

METHOD

Current practices for progress monitoring during language interventions with children with autism and minimal verbal skills are reviewed. A phonemic feature scoring tool is provided to aid clinicians in assessing the accuracy and consistency of expressive word productions. The authors illustrate the use of phonemic feature scoring as a progress-monitoring tool for two children with autism and minimal verbal skills, contrasting the phonemic feature scoring system to correct/incorrect, phoneme-level, and whole-word scoring.

RESULTS

Case 1 demonstrates a scenario where the child's speech intelligibility is low and clinical use of the phonemic feature scoring system captures discrete changes in speech production progress not represented by correct/incorrect, phoneme-level, and whole-word scoring. However, Case 2 represents a situation where once a child's speech intelligibility improves, the phonemic feature scoring system is no longer needed, and correct/incorrect scoring may be sufficient.

CONCLUSION

The phonemic feature scoring system allows clinicians to track phonemic feature changes in word productions and provides detailed progress monitoring information, leading to adaptations of the intervention for each individual.

Identifying Links Between Latent Memory and Speech Recognition Factors

OBJECTIVES

The link between memory ability and speech recognition accuracy is often examined by correlating summary measures of performance across various tasks, but interpretation of such correlations critically depends on assumptions about how these measures map onto underlying factors of interest. The present work presents an alternative approach, wherein latent factor models are fit to trial-level data from multiple tasks to directly test hypotheses about the underlying structure of memory and the extent to which latent memory factors are associated with individual differences in speech recognition accuracy. Latent factor models with different numbers of factors were fit to the data and compared to one another to select the structures which best explained vocoded sentence recognition in a two-talker masker across a range of target-to-masker ratios, performance on three memory tasks, and the link between sentence recognition and memory.

DESIGN

Young adults with normal hearing (N = 52 for the memory tasks, of which 21 participants also completed the sentence recognition task) completed three memory tasks and one sentence recognition task: reading span, auditory digit span, visual free recall of words, and recognition of 16-channel vocoded Perceptually Robust English Sentence Test Open-set sentences in the presence of a two-talker masker at target-to-masker ratios between +10 and 0 dB. Correlations between summary measures of memory task performance and sentence recognition accuracy were calculated for comparison to prior work, and latent factor models were fit to trial-level data and compared against one another to identify the number of latent factors which best explains the data. Models with one or two latent factors were fit to the sentence recognition data and models with one, two, or three latent factors were fit to the memory task data. Based on findings with these models, full models that linked one speech factor to one, two, or three memory factors were fit to the full data set. Models were compared via Expected Log pointwise Predictive Density and post hoc inspection of model parameters.

RESULTS

Summary measures were positively correlated across memory tasks and sentence recognition. Latent factor models revealed that sentence recognition accuracy was best explained by a single factor that varied across participants. Memory task performance was best explained by two latent factors, of which one was generally associated with performance on all three tasks and the other was specific to digit span recall accuracy at lists of six digits or more. When these models were combined, the general memory factor was closely related to the sentence recognition factor, whereas the factor specific to digit span had no apparent association with sentence recognition.

CONCLUSIONS

Comparison of latent factor models enables testing hypotheses about the underlying structure linking cognition and speech recognition. This approach showed that multiple memory tasks assess a common latent factor that is related to individual differences in sentence recognition, although performance on some tasks was associated with multiple factors. Thus, while these tasks provide some convergent assessment of common latent factors, caution is needed when interpreting what they tell us about speech recognition.

Object Shape and Depth of Word Representations in Preschoolers

This study examined the effect of a shape cue (i.e., co-speech gesture) on word depth. We taught 23 preschoolers (M = 3;5 years, SD = 5.82) novel objects with either shape (SHP) or indicator (IND) gestures. SHP gestures mimicked object form, but IND gestures were not semantically related to the object (e.g., an upward-facing palm, extended toward the object). Each object had a unique IND or SHP gesture. Outcome measures reflected richer semantic and phonological learning in the SHP than in the IND condition. In the SHP condition, preschoolers (a) expressed more semantic knowledge, (b) said more sounds in names, and (c) generalized more names to untaught objects. There were also fewer disruptions to prime picture names in the SHP condition; we discuss the benefit of a co-speech shape gesture to capitalize on well-established statistical word learning patterns.

The impact of age on the treatment of late-acquired sounds in children with speech sound disorders

The question of 'when' to treat speech sounds is often posed in the context of normative data. The new normative data suggest that speech sounds such as /ɹ/ and /l/ are acquired earlier than previously thought. The present study compared the treatment of late-acquired sounds between two age groups of English-speaking children: Young children (4-5) and Old children (7-8). Eight monolingual children with speech sound disorder (SSD) participated in the study. Each child received a criterion-based, standardised, two-phase therapy protocol. Treatment efficacy was measured by examining children's accuracy on real world speech probes. Treatment efficiency was measured by calculating the number of sessions required to meet the exit criterion and the mean session duration. For treatment efficacy, young children learned treated sounds as effectively as oldchildren did. For treatment efficiency, both groups required a comparable number of sessions, but young children required longer sessions than old children. The results suggest that delaying treatment of individual speech sounds is unnecessary and that a range of sounds should be considered as potential treatment targets.

Can Retrieval Practice Facilitate Verb Learning in Children With Developmental Language Disorder and Their Peers With Typical Language Development?

PURPOSE

Children with developmental language disorder (DLD) have well-documented verb learning difficulties. In this study, we asked whether the inclusion of retrieval practice during the learning period would facilitate these children's verb learning relative to a similar procedure that provided no retrieval opportunities.

METHOD

Eleven children with DLD (M age = 60.09 months) and 12 children with typical language development (TD; M age = 59.92 months) learned four novel verbs in a repeated spaced retrieval (RSR) condition and four novel verbs in a repeated study (RS) condition. The words in the two conditions were heard an equal number of times, in the context of video-recorded actors performing novel actions.

RESULTS

Recall testing immediately after the learning period and 1 week later revealed greater recall for novel verbs in the RSR condition than for novel verbs in the RS condition. This was true for both groups, and for immediate as well as 1-week testing. The RSR advantage remained when children had to recall the novel verbs while watching new actors perform the novel actions. However, when tested in contexts requiring the children to inflect the novel verbs with -ing for the first time, the children with DLD were much less likely to do so than their peers with TD. Even words in the RSR condition were only inconsistently inflected.

CONCLUSIONS

Retrieval practice provides benefits to verb learning-an important finding given the challenges that verbs present to children with DLD. However, these benefits do not appear to automatically translate to the process of adding inflections to newly learned verbs but rather appear to be limited to the operations of learning the verbs' phonetic forms and mapping these forms onto associated actions.

Using Multivariate Adaptive Regression Splines to Predict Lexical Characteristics' Influence on Word Learning in First Through Third Graders

PURPOSE

Identifying appropriate targets for vocabulary instruction and determining the optimal sequence for instruction continue to be a challenge. The purpose of this study is to investigate how previously studied lexical characteristics collectively influence children's word learning.

METHOD

A secondary data analysis was conducted using the word learning results of 350 first-, second-, and third-grade students who participated in an investigation examining the effects of a supplemental vocabulary intervention. We investigated the influence of the following lexical characteristics on the learning of 377 words: word frequency, level of concreteness, phonotactic probabilities, neighborhood density, and age of acquisition using multivariate adaptive regression splines (MARS).

RESULTS

MARS modeled the influence lexical characteristics had on word learning and determined the relative importance of each variable for each grade-level model. Results revealed age of acquisition was the most important factor related to word learning in all grades, but contributions of other lexical characteristics and their level of importance differed across models. All respective models fit well, with root-mean-square error values ranging from 0.11 to 0.15 and generalized cross validation scores of 0.01 and 0.03.

CONCLUSIONS

Nuanced information from the MARS analysis provides insights into how lexical characteristics affect word learning differently for children in different grade levels. This information is key to understanding the vocabulary acquisition of school-aged children. The findings from this research have the potential to inform the development of a word selection framework that will organize vocabulary targets into an appropriate sequence based on relevant predictors.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21899529.

Developmental differences in EEG oscillations supporting the identification of novel word meaning from context

Implicit learning about new words by picking up on associative information in the contexts they appear in is an important aspect of vocabulary growth. The current study investigated the neural correlates that underlie how school-aged children and adolescents identify the meaning of novel words embedded within sentence contexts. Importantly, we examine how differences in the brain response to novel words and their context differ as a function of 1) explicit learning success, i.e., whether novel word meanings can be correctly estimated in isolation after a learning opportunity, and 2) individual differences in offline language aptitude as well as age across our cohort (N = 82; 8-16 years). Using a regression-based analysis, we identified the unique influence of these individuals difference metrics by using both measures within the same series of models. The most notable finding from our analysis was a frequency-specific dissociation between the way age and language abilities held relationships with task-relevant oscillatory activity during the novel word meaning task: language abilities associated with task-relevant changes in beta band activity during sentence processing, while age associated with task-relevant changes in theta band activity during pseudoword processing. These effects reflect the how the neural correlates of mapping semantic meaning from sentence contexts-an important skill for word learning-is uniquely influenced by the maturity of language abilities as well as age.

Can Closed-Set Word Recognition Differentially Assess Vowel and Consonant Perception for School-Age Children With and Without Hearing Loss?

PURPOSE

Vowels and consonants play different roles in language acquisition and speech recognition, yet standard clinical tests do not assess vowel and consonant perception separately. As a result, opportunities for targeted intervention may be lost. This study evaluated closed-set word recognition tests designed to rely predominantly on either vowel or consonant perception and compared results with sentence recognition scores.

METHOD

Participants were children (5-17 years of age) and adults (18-38 years of age) with normal hearing and children with sensorineural hearing loss (7-17 years of age). Speech reception thresholds (SRTs) were measured in speech-shaped noise. Children with hearing loss were tested with their hearing aids. Word recognition was evaluated using a three-alternative forced-choice procedure, with a picture-pointing response; monosyllabic target words varied with respect to either consonant or vowel content. Sentence recognition was evaluated for low- and high-probability sentences. In a subset of conditions, stimuli were low-pass filtered to simulate a steeply sloping hearing loss in participants with normal hearing.

RESULTS

Children's SRTs improved with increasing age for words and sentences. Low-pass filtering had a larger effect for consonant-variable words than vowel-variable words for both children and adults with normal hearing, consistent with the greater high-frequency content of consonants. Children with hearing loss tested with hearing aids tended to perform more poorly than age-matched children with normal hearing, particularly for sentence recognition, but consonant- and vowel-variable word recognition did not appear to be differentially affected by the amount of high- and low-frequency hearing loss.

CONCLUSIONS

Closed-set recognition of consonant- and vowel-variable words appeared to differentially evaluate vowel and consonant perception but did not vary by configuration of hearing loss in this group of pediatric hearing aid users. Word scores obtained in this manner do not fully characterize the auditory abilities necessary for open-set sentence recognition, but they do provide a general estimate.

The effect of speaker reliability on word learning in monolingual and bilingual children

The present study examined the effect of speaker reliability on novel word learning in 4- and 5-year-old English-speaking monolingual (N=25) and Spanish-English bilingual (N=25) children, using an eye-tracking paradigm. Results revealed that children retained novel labels taught by both the reliable and the unreliable speaker. Yet, time-course analyses revealed that children showed faster word recognition in the reliable condition but demonstrated more persistent looks to target in the unreliable condition. This suggests that speaker reliability impacts the time-course of retrieval, but not the ultimate retention of novel words. No group differences were observed in children's overall accuracy of novel word learning, although monolingual and bilingual children did demonstrate subtle differences in the time-course of novel word recognition. Together, the findings suggest that while speaker cues shape the process by which children recognize newly-learned words, language experience has minimal influence on this process.

Neural oscillations reflect meaning identification for novel words in context

During language processing, people make rapid use of contextual information to promote comprehension of upcoming words. When new words are learned implicitly, information contained in the surrounding context can provide constraints on their possible meaning. In the current study, EEG was recorded as participants listened to a series of three sentences, each containing an identical target pseudoword, with the aim of using contextual information in the surrounding language to identify a meaning representation for the novel word. In half of trials, sentences were semantically coherent so that participants could develop a single representation for the novel word that fit all contexts. Other trials contained unrelated sentence contexts so that meaning associations were not possible. We observed greater theta band enhancement over the left-hemisphere across central and posterior electrodes in response to pseudowords processed across semantically related compared to unrelated contexts. Additionally, relative alpha and beta band suppression was increased prior to pseudoword onset in trials where contextual information more readily promoted pseudoword-meaning associations. Under the hypothesis that theta enhancement indexes processing demands during lexical access, the current study provides evidence for selective online memory retrieval to novel words learned implicitly in a spoken context.

Word learning in monolingual and bilingual children: The influence of speaker eye-gaze

The current study examined the impact of a speaker's gaze on novel-word learning in 4-5-year old monolingual (N = 23) and bilingual children (N = 24). Children were taught novel words when the speaker looked at the object both times while labeling it (consistent) and when the speaker looked at the object only the first time (inconsistent). During teaching, bilingual children differentiated between the target object (that matched the label) and non-target object (that did not match the label) earlier than the monolingual children on trials without eye-gaze information. However, during testing, monolingual children showed more robust retention of novel words than bilingual children in both conditions. Findings suggest that bilingualism shapes children's attention to eye-gaze during word learning, but that, ultimately, there is no bilingual advantage for utilizing this cue in the service of word retention.

Acoustic-Phonetic Mismatches Impair Serial Recall of Degraded Words

Sequences of phonologically similar words are more difficult to remember than phonologically distinct sequences. This study investigated whether this difficulty arises in the acoustic similarity of auditory stimuli or in the corresponding phonological labels in memory. Participants reconstructed sequences of words which were degraded with a vocoder. We manipulated the phonological similarity of response options across two groups. One group was trained to map stimulus words onto phonologically similar response labels which matched the recorded word; the other group was trained to map words onto a set of plausible responses which were mismatched from the original recordings but were selected to have less phonological overlap. Participants trained on the matched responses were able to learn responses with less training and recall sequences more accurately than participants trained on the mismatched responses, even though the mismatched responses were more phonologically distinct from one another and participants were unaware of the mismatch. The relative difficulty of recalling items in the correct position was the same across both sets of response labels. Mismatched responses impaired recall accuracy across all positions except the final item in each list. These results are consistent with the idea that increased difficulty of mapping acoustic stimuli onto phonological forms impairs serial recall. Increased mapping difficulty could impair retention of memoranda and impede consolidation into phonological forms, which would impair recall in adverse listening conditions.

Neural oscillations reveal differences in the process of word learning among school-aged children from lower socioeconomic status backgrounds

Building a robust vocabulary in grade school is essential for academic success. Children from lower socioeconomic status (SES) households on average perform below their higher SES peers on word learning tasks, negatively impacting their vocabulary; however, significant variability exists within this group. Many children from low SES homes perform as well as, or better than, their higher SES peers on measures of word learning. The current study addresses what processes underlie this variability, by comparing the neural oscillations of 44 better versus worse word learners (ages 8-15 years) from lower SES households as they infer the meaning of unknown words. Better word learners demonstrated increases in theta and beta power as a word was learned, whereas worse word learners exhibited decreases in alpha power. These group differences in neural oscillatory engagement during word learning indicate there may be different strategies employed based on differences in children's skills. Notably, children with greater vocabulary knowledge are more likely to exhibit larger beta increases; a strategy which is associated with better word learning. This sheds new light on the mechanisms that support word learning in children from low SES households.

The role of speaker eye gaze and mutual exclusivity in novel word learning by monolingual and bilingual children

The current study examined the combined effect of a speaker's eye gaze and mutual exclusivity (ME) on novel word retention in monolingual and bilingual children. A novel object was presented with a familiar object, and children were taught new labels for objects under two conditions. In the Align condition, the speaker's gaze and the ME cue provided the same information (the speaker looked at the novel object while labeling it with a novel name). In the Conflict condition, the speaker's gaze and the ME cue provided competing information (the speaker looked at the familiar object while labeling it with a novel name). Using a visual world eye-tracking paradigm, children's retention was assessed by testing novel objects with novel labels and by testing the familiar objects with novel labels. We found that all children successfully retained the novel labels for novel objects when both eye gaze and ME provided the same information. However, when the cues conflicted, bilingual children did not perform above chance for either novel objects or familiar objects. In contrast, monolingual children demonstrated retention of novel labels for familiar objects but not for novel objects. Together, the findings suggest that redundant cues benefit word retention in all children regardless of linguistic background. Furthermore, when speaker gaze and ME conflict, bilingual children appear to disregard both cues during retention, whereas monolingual children may be more willing to retain novel labels for familiar words, suggesting that they prioritize a speaker's eye gaze over ME.

Interactions Between Item Set and Vocoding in Serial Recall

OBJECTIVES

Serial recall of digits is frequently used to measure short-term memory span in various listening conditions. However, the use of digits may mask the effect of low quality auditory input. Digits have high frequency and are phonologically distinct relative to one another, so they should be easy to identify even with low quality auditory input. In contrast, larger item sets reduce listener ability to strategically constrain their expectations, which should reduce identification accuracy and increase the time and/or cognitive resources needed for identification when auditory quality is low. This diminished accuracy and increased cognitive load should interfere with memory for sequences of items drawn from large sets. The goal of this work was to determine whether this predicted interaction between auditory quality and stimulus set in short-term memory exists, and if so, whether this interaction is associated with processing speed, vocabulary, or attention.

DESIGN

We compared immediate serial recall within young adults with normal hearing across unprocessed and vocoded listening conditions for multiple stimulus sets. Stimulus sets were lists of digits (1 to 9), consonant-vowel-consonant (CVC) words (chosen from a list of 60 words), and CVC nonwords (chosen from a list of 50 nonwords). Stimuli were unprocessed or vocoded with an eight-channel noise vocoder. To support interpretation of responses, words and nonwords were selected to minimize inclusion of multiple phonemes from within a confusion cluster. We also measured receptive vocabulary (Peabody Picture Vocabulary Test [PPVT-4]), sustained attention (test of variables of attention [TOVA]), and repetition speed for individual items from each stimulus set under both listening conditions.

RESULTS

Vocoding stimuli had no impact on serial recall of digits, but reduced memory span for words and nonwords. This reduction in memory span was attributed to an increase in phonological confusions for nonwords. However, memory span for vocoded word lists remained reduced even after accounting for common phonetic confusions, indicating that lexical status played an additional role across listening conditions. Principal components analysis found two components that explained 84% of the variance in memory span across conditions. Component one had similar load across all conditions, indicating that participants had an underlying memory capacity, which was common to all conditions. Component two was loaded by performance in the vocoded word and nonword conditions, representing the sensitivity of memory span to vocoding of these stimuli. The order in which participants completed listening conditions had a small effect on memory span that could not account for the effect of listening condition. Repetition speed was fastest for digits, slower for words, and slowest for nonwords. On average, vocoding slowed repetition speed for all stimuli, but repetition speed was not predictive of individual memory span. Vocabulary and attention showed no correlation with memory span.

CONCLUSIONS

Our results replicated previous findings that low quality auditory input can impair short-term memory, and demonstrated that this impairment is sensitive to stimulus set. Using multiple stimulus sets in degraded listening conditions can isolate memory capacity (in digit span) from impaired item identification (in word and nonword span), which may help characterize the relationship between memory and speech recognition in difficult listening conditions.

Serial Recall Predicts Vocoded Sentence Recognition Across Spectral Resolutions

Purpose The goal of this study was to determine how various aspects of cognition predict speech recognition ability across different levels of speech vocoding within a single group of listeners. Method We tested the ability of young adults (N = 32) with normal hearing to recognize Perceptually Robust English Sentence Test Open-set (PRESTO) sentences that were degraded with a vocoder to produce different levels of spectral resolution (16, eight, and four carrier channels). Participants also completed tests of cognition (fluid intelligence, short-term memory, and attention), which were used as predictors of sentence recognition. Sentence recognition was compared across vocoder conditions, predictors were correlated with individual differences in sentence recognition, and the relationships between predictors were characterized. Results PRESTO sentence recognition performance declined with a decreasing number of vocoder channels, with no evident floor or ceiling performance in any condition. Individual ability to recognize PRESTO sentences was consistent relative to the group across vocoder conditions. Short-term memory, as measured with serial recall, was a moderate predictor of sentence recognition (ρ = 0.65). Serial recall performance was constant across vocoder conditions when measured with a digit span task. Fluid intelligence was marginally correlated with serial recall, but not sentence recognition. Attentional measures had no discernible relationship to sentence recognition and a marginal relationship with serial recall. Conclusions Verbal serial recall is a substantial predictor of vocoded sentence recognition, and this predictive relationship is independent of spectral resolution. In populations that show variable speech recognition outcomes, such as listeners with cochlear implants, it should be possible to account for the independent effects of spectral resolution and verbal serial recall in their speech recognition ability. Supplemental Material https://doi.org/10.23641/asha.12021051.

Quantifying the Effects of Background Speech Babble on Preschool Children's Novel Word Learning in a Multisession Paradigm: A Preliminary Study

Purpose This study tested the effects of background speech babble on novel word learning in preschool children with a multisession paradigm. Method Eight 3-year-old children were exposed to a total of 8 novel word-object pairs across 2 story books presented digitally. Each story contained 4 novel consonant-vowel-consonant nonwords. Children were exposed to both stories, one in quiet and one in the presence of 4-talker babble presented at 0-dB signal-to-noise ratio. After each story, children's learning was tested with a referent selection task and a verbal recall (naming) task. Children were exposed to and tested on the novel word-object pairs on 5 separate days within a 2-week span. Results A significant main effect of session was found for both referent selection and verbal recall. There was also a significant main effect of exposure condition on referent selection performance, with more referents correctly selected for word-object pairs that were presented in quiet compared to pairs presented in speech babble. Finally, children's verbal recall of novel words was statistically better than baseline performance (i.e., 0%) on Sessions 3-5 for words exposed in quiet, but only on Session 5 for words exposed in speech babble. Conclusions These findings suggest that background speech babble at 0-dB signal-to-noise ratio disrupts novel word learning in preschool-age children. As a result, children may need more time and more exposures of a novel word before they can recognize or verbally recall it.

Investigating Implicit and Explicit Word Learning in School-age Children Using a Combined Behavioral-Event Related Potential (ERP) Approach

One challenge in word learning research is how to operationalize learning. We combined behavioral measures with EEG to examine implicit and explicit recognition of words previously introduced with or without meaning in an incidental learning task. Participants (8-11-year-old children) were not able to recognize previously introduced nonsense words and better performance on the learning task resulted in poorer word recognition. The N400 amplitude differed between nonsense words with meaning versus nonsense words no meaning and novel nonsense words. Results indicate that introducing a nonsense word with meaning does not aid in explicit word learning but improves implicit word learning.

Using the N400 event-related potential to study word learning from context in children from low- and higher-socioeconomic status homes

Children from low-socioeconomic status (SES) homes have significantly smaller vocabularies than their higher-SES peers, a gap that increases over the course of the school years. One reason for the increase in this vocabulary gap during the school years is that children from low-SES homes learn fewer words from context than their higher-SES peers. To better understand how the process of word learning from context might differ in children related to SES, we investigated changes in the N400 event-related potential (ERP) as children from low- and higher-SES homes learned new words using only the surrounding linguistic context. There were no differences in the N400 response to known words related to SES. In response to the target word being learned, children from higher-SES homes, like adults in previous studies, exhibited an attenuation of the N400 across exposures as they attached meaning to it. Children from low-SES homes did not show this same attenuation. These findings support previous work showing that children from low-SES homes may have differences or more variability in the neural components supporting language processing, and they extend previous work to illustrate how this variability may relate to word learning and, ultimately, vocabulary growth.

Comparing Word Characteristic Effects on Vocabulary of Children with Cochlear Implants

Many studies have evaluated overall vocabulary knowledge of children who use cochlear implants, but there has been minimal focus on how word form characteristics affect this knowledge. This study evaluates the effects of neighborhood density and phonotactic probability on the expressive vocabulary of 81 children between five and seven years old (n = 27 cochlear implant users, n = 27 children matched for chronological age, and n = 27 children matched for vocabulary size). Children were asked to name pictures associated with words that have common and rare phonotactic probability and high and sparse neighborhood density. Results indicate that children with cochlear implants, similar to both groups of children with typical hearing, tend to know words with common probability/high density or with rare probability/ sparse density. Patterns of word knowledge for children with cochlear implants mirrored younger children matched for vocabulary size rather than age-matched children with typical hearing.

The effect of neighborhood density on children's word learning in noise

Many studies have addressed the effect of neighborhood density (phonological similarity among words) on word learning in quiet listening conditions. We explored how noise influences the effect of neighborhood density on children's word learning. One-hundred-and-two preschoolers learned nonwords varied in neighborhood density in one of four listening conditions: quiet, +15 dB signal-to-noise ratio (SNR), +6 dB SNR, and 0 dB SNR. Results showed that a high-density advantage for children under quiet listening condition was significantly reduced as noise increased. This finding implies an adverse impact of noise on long-term outcomes of word learning.

Pairing New Words With Unfamiliar Objects: Comparing Children With and Without Cochlear Implants

PURPOSE

This study investigates differences between preschool children with cochlear implants and age-matched children with normal hearing during an initial stage in word learning to evaluate whether they (a) match novel words to unfamiliar objects and (b) solicit information about unfamiliar objects during play.

METHOD

Twelve preschool children with cochlear implants and 12 children with normal hearing matched for age completed 2 experimental tasks. In the 1st task, children were asked to point to a picture that matched either a known word or a novel word. In the 2nd task, children were presented with unfamiliar objects during play and were given the opportunity to ask questions about those objects.

RESULTS

In Task 1, children with cochlear implants paired novel words with unfamiliar pictures in fewer trials than children with normal hearing. In Task 2, children with cochlear implants were less likely to solicit information about new objects than children with normal hearing. Performance on the 1st task, but not the 2nd, significantly correlated with expressive vocabulary standard scores of children with cochlear implants.

CONCLUSION

This study provides preliminary evidence that children with cochlear implants approach mapping novel words to and soliciting information about unfamiliar objects differently than children with normal hearing.

A Web-based interface to calculate phonotactic probability for words and nonwords in Modern Standard Arabic

A number of databases (Storkel Behavior Research Methods, 45, 1159-1167, 2013) and online calculators (Vitevitch & Luce Behavior Research Methods, Instruments, and Computers, 36, 481-487, 2004) have been developed to provide statistical information about various aspects of language, and these have proven to be invaluable assets to researchers, clinicians, and instructors in the language sciences. The number of such resources for English is quite large and continues to grow, whereas the number of such resources for other languages is much smaller. This article describes the development of a Web-based interface to calculate phonotactic probability in Modern Standard Arabic (MSA). A full description of how the calculator can be used is provided. It can be freely accessed at http://phonotactic.drupal.ku.edu/ .

Implementing Evidence-Based Practice: Selecting Treatment Words to Boost Phonological Learning

Purpose

Word selection has typically been thought of as an inactive ingredient in phonological treatment, but emerging evidence suggests that word selection is an active ingredient that can impact phonological learning. The goals of this tutorial are to (a) review the emerging single-subject evidence on the influence of word characteristics on phonological learning in clinical treatment, (b) outline hypotheses regarding the mechanism of action of word characteristics, and (c) provide resources to support clinicians incorporating word selection as an active ingredient in their approach to phonological treatment.

Method

Research demonstrating the influence of the word frequency, neighborhood density, age of acquisition, and lexicality of treatment stimuli on phonological learning is summarized. The mechanism of action for each characteristic is hypothesized. Methods from the research studies are used to create a free set of evidence-based treatment materials targeting most of the mid-8 and late-8 consonants.

Results

Clinicians have numerous evidence-based options to consider when selecting stimuli for phonological treatment including (a) high-frequency and high-density words, (b) low-frequency and high-density words, (c) high-frequency and mixed-density words, (d) low-frequency and late-acquired words, and (e) nonwords.

Conclusion

Incorporating word characteristics into phonological treatment may boost phonological learning.

KU ScholarWorks Supplemental Material

http://hdl.handle.net/1808/24768

Reverse production effect: children recognize novel words better when they are heard rather than produced

This research investigates the effect of production on 4.5- to 6-year-old children's recognition of newly learned words. In Experiment 1, children were taught four novel words in a produced or heard training condition during a brief training phase. In Experiment 2, children were taught eight novel words, and this time training condition was in a blocked design. Immediately after training, children were tested on their recognition of the trained novel words using a preferential looking paradigm. In both experiments, children recognized novel words that were produced and heard during training, but demonstrated better recognition for items that were heard. These findings are opposite to previous results reported in the literature with adults and children. Our results show that benefits of speech production for word learning are dependent on factors such as task complexity and the developmental stage of the learner.

Word-learning performance of children with and without cochlear implants given synchronous and asynchronous cues

This study sought to evaluate the effects of synchronous and asynchronous auditory-visual cues on the word-learning performance of children with cochlear implants and children with normal hearing matched for chronological age. Children with cochlear implants (n = 9) who had worn the implant for less than one year and children matched for chronological age (n = 9) participated in rapid word-learning trials. Children with cochlear implants did not learn words in either the synchronous or asynchronous condition (U = 49.5, p = .99; d = 0.05). Children with normal hearing learned more words in the synchronous rather than asynchronous condition (U = 78.5, p = .04; d = 0.95). These findings represent a first step toward determining how task-level factors influence the lexical outcomes of children with cochlear implants.

Reading Skill and Exposure to Orthography Influence Speech Production

Orthographic experience during the acquisition of novel words may influence production processing in proficient readers. Previous work indicates interactivity among lexical, phonological, and articulatory processing; we hypothesized that experience with orthography can also influence phonological processing. Phonetic accuracy and articulatory stability were measured as adult, proficient readers repeated and read aloud nonwords, presented in auditory or written modalities and with variations in orthographic neighborhood density. Accuracy increased when participants had read the nonwords earlier in the session, but not when they had only heard them. Articulatory stability increased with practice, regardless of whether nonwords were read or heard. Word attack skills, but not reading comprehension, predicted articulatory stability. Findings indicate that kinematic and phonetic accuracy analyses provide insight into how orthography influences implicit language processing.

Dense neighborhoods and mechanisms of learning: evidence from children with phonological delay

There is a noted advantage of dense neighborhoods in language acquisition, but the learning mechanism that drives the effect is not well understood. Two hypotheses--long-term auditory word priming and phonological working memory--have been advanced in the literature as viable accounts. These were evaluated in two treatment studies enrolling twelve children with phonological delay. Study 1 exposed children to dense neighbors versus non-neighbors before training sound production in evaluation of the priming hypothesis. Study 2 exposed children to the same stimuli after training sound production as a test of the phonological working memory hypothesis. Results showed that neighbors led to greater phonological generalization than non-neighbors, but only when presented prior to training production. There was little generalization and no differential effect of exposure to neighbors or non-neighbors after training production. Priming was thus supported as a possible mechanism of learning behind the dense neighborhood advantage in phonological acquisition.

Investigating a Multimodal Intervention for Children With Limited Expressive Vocabularies Associated With Autism

PURPOSE

This study investigated a new intervention package aimed at increasing expressive word learning by school-age children with autism who have limited expressive vocabularies. This pilot investigation was intended to show proof of concept.

METHOD

Ten children between the ages of 6 and 10 years participated, with educational diagnoses of autism and limited expressive vocabularies at the outset of the study. A multimodal intervention composed of speech sound practice and augmentative and alternative communication was used to teach individualized vocabulary words that were selected on the basis of initial speech sound repertoires and principles of phonotactic probability and neighborhood density. A multiple-probe design was used to evaluate learning outcomes.

RESULTS

Five children showed gains in spoken-word learning across successive word sets (high responders). Five children did not meet learning criteria (low responders). Comparisons of behaviors measured prior to intervention indicated that high responders had relatively higher skills in receptive language, prelinguistic communication, vocal/verbal imitation, adaptive behavior, and consonant productions.

CONCLUSIONS

The intervention package holds promise for improving spoken word productions for some children with autism who have limited expressive vocabularies. Further research is needed to better describe who may most benefit from this approach as well as investigate generalized benefits to untaught contexts and targets.

Talker familiarity and spoken word recognition in school-age children

Research with adults has shown that spoken language processing is improved when listeners are familiar with talkers' voices, known as the familiar talker advantage. The current study explored whether this ability extends to school-age children, who are still acquiring language. Children were familiarized with the voices of three German-English bilingual talkers and were tested on the speech of six bilinguals, three of whom were familiar. Results revealed that children do show improved spoken language processing when they are familiar with the talkers, but this improvement was limited to highly familiar lexical items. This restriction of the familiar talker advantage is attributed to differences in the representation of highly familiar and less familiar lexical items. In addition, children did not exhibit accent-general learning; despite having been exposed to German-accented talkers during training, there was no improvement for novel German-accented talkers.

Effects of verb familiarity on finiteness marking in children with specific language impairment

PURPOSE

Children with specific language impairment (SLI) have known deficits in the verb lexicon and finiteness marking. This study investigated a potential relationship between these 2 variables in children with SLI and 2 control groups considering predictions from 2 different theoretical perspectives, morphosyntactic versus morphophonological.

METHOD

Children with SLI, age-equivalent, and language-equivalent (LE) control children (n=59) completed an experimental sentence imitation task that generated estimates of children's finiteness accuracy under 2 levels of verb familiarity--familiar real verbs versus unfamiliar real verbs--in clausal sites marked for finiteness. Imitations were coded and analyzed for overall accuracy as well as finiteness marking and verb root imitation accuracy.

RESULTS

Statistical comparisons revealed that children with SLI did not differ from LE children and were less accurate than age-equivalent children on all dependent variables: overall imitation, finiteness marking imitation, and verb root imitation accuracy. A significant Group×Condition interaction for finiteness marking revealed lower levels of accuracy on unfamiliar verbs for the SLI and LE groups only.

CONCLUSIONS

Findings indicate a relationship between verb familiarity and finiteness marking in children with SLI and younger controls and help clarify the roles of morphosyntax, verb lexicon, and morphophonology.

Online learning from input versus offline memory evolution in adult word learning: effects of neighborhood density and phonologically related practice

PURPOSE

In this study, the authors investigated adult word learning to determine how neighborhood density and practice across phonologically related training sets influence online learning from input during training versus offline memory evolution during no-training gaps.

METHOD

Sixty-one adults were randomly assigned to learn low- or high-density nonwords. Within each density condition, participants were trained on one set of words and then were trained on a second set of words, consisting of phonological neighbors of the first set. Learning was measured in a picture-naming test. Data were analyzed using multilevel modeling and spline regression.

RESULTS

Steep learning during input was observed, with new words from dense neighborhoods and new words that were neighbors of recently learned words (i.e., second-set words) being learned better than other words. In terms of memory evolution, large and significant forgetting was observed during 1-week gaps in training. Effects of density and practice during memory evolution were opposite of those during input. Specifically, forgetting was greater for high-density and second-set words than for low-density and first-set words.

CONCLUSION

High phonological similarity, regardless of source (i.e., known words or recent training), appears to facilitate online learning from input but seems to impede offline memory evolution.

The influence of two cognitive-linguistic variables on incidental word learning in 5-year-olds

The relation between incidental word learning and two cognitive-linguistic variables--phonological memory and phonological awareness--is not fully understood. Thirty-five typically developing, 5-year-old, preschool children participated in a study examining the association between phonological memory, phonological awareness, and incidental word learning. Children were exposed to target words in a read-aloud story that accompanied a wordless picture book. Target word comprehension was assessed before and after two readings of the story. Phonological awareness predicted incidental word learning but phonological memory did not. The influence of phonological awareness and phonological memory on word learning may be dependent on the demands of the word learning task.

The effect of incremental changes in phonotactic probability and neighborhood density on word learning by preschool children

PURPOSE

Phonotactic probability or neighborhood density has predominately been defined through the use of gross distinctions (i.e., low vs. high). In the current studies, the authors examined the influence of finer changes in probability (Experiment 1) and density (Experiment 2) on word learning.

METHOD

The authors examined the full range of probability or density by sampling 5 nonwords from each of 4 quartiles. Three- and 5-year-old children received training on nonword-nonobject pairs. Learning was measured in a picture-naming task immediately following training and 1 week after training. Results were analyzed through the use of multilevel modeling.

RESULTS

A linear spline model best captured nonlinearities in phonotactic probability. Specifically, word learning improved as probability increased in the lowest quartile, worsened as probability increased in the mid-low quartile, and then remained stable and poor in the 2 highest quartiles. An ordinary linear model sufficiently described neighborhood density. Here, word learning improved as density increased across all quartiles.

CONCLUSION

Given these different patterns, phonotactic probability and neighborhood density appear to influence different word learning processes. Specifically, phonotactic probability may affect recognition that a sound sequence is an acceptable word in the language and is a novel word for the child, whereas neighborhood density may influence creation of a new representation in long-term memory.