Mispronunciation Detection Task Research Articles

Production and perception of stop voicing in Central Australian Aboriginal English: A cross-generational study

ABSTRACT This paper reports on a series of studies investigating the production and perception of stop voicing contrasts in speakers of Central Australian Aboriginal English (CAAE; Alice Springs, Australia). Study 1 investigated Voice Onset Time (VOT) and Constriction Duration (CD) in stop consonants in naturalistic adult speech, and the speakers produced a VOT-based voicing distinction in word-initial stops, while medial voiceless stops differ from voiced stops in having both longer VOTs and longer CDs, at least for the syllable onset position. Study 2 investigated the implementation of stop voicing contrasts (VOT and CD) in a cohort of child CAAE speakers, and the results are consistent with the adult CAAE data, suggesting predictable intergenerational transmission. Finally, Study 3 tested child speakers’ perception of stop voicing contrasts using a mispronunciation detection task, where the participants demonstrated above-chance performance for the voicing distinction across all places of articulation. Together, the findings suggest that CAAE has phonemic stop voicing distinctions, like Mainstream Australian English, and that CAAE medial stops are jointly cued by both VOT and CD, a feature shared with the contact language, Kriol.

Perception of Correctly and Incorrectly Produced Words in Children With and Without Phonological Speech Sound Disorders.

Purpose The purpose of this study was to examine the perception of correctly and incorrectly produced words in children with and without phonological speech sound disorder (SSD) with similar vocabulary and language skills. Method Thirty-six monolingual English-speaking children aged 4 and 5 years, half with SSD and half with typical speech and language skills, participated in this study. Participants completed standardized speech and language tests as well as a mispronunciation detection task targeting omissions and substitutions of the phonemes /k, s, ɹ/ in five word positions/shapes. Results The children with SSD obtained significantly lower perceptual accuracy than the children with typical development. There was no statistically significant effect for phoneme. Omissions were more likely to be detected by both groups of participants compared with substitutions, and children with SSD had greater difficulty identifying substitutions as incorrectly produced words. Conclusions Speech perception difficulties may be a distinguishing feature of children with phonological SSD and without concomitant language difficulties. Further research is needed to investigate specific speech contexts in which perception predicts accurate production in children with SSD.

Asymmetries in the exploitation of phonetic features for word recognition.

French listeners' reliance on voicing, manner, and place was tested in a mispronunciation detection task. Mispronounced words were more likely to be recognized when the mispronunciation concerned voicing rather than manner or place. This indicates that listeners rely less on the former than on the latter for the purposes of word recognition. Further, the role of visual cues to phonetic features was explored by the task being conducted in both an audio-only and an audiovisual version, but no effect of modality was found. Discussion focuses on crosslinguistic comparisons and lexical factors that might influence the weight of individual features.

Asymmetries in Early Word Recognition: The Case of Stops and Fricatives

Toddlers' discrimination of native phonemic contrasts is generally unproblematic. Yet using those native contrasts in word learning and word recognition can be more challenging. In this article, we investigate perceptual versus phonological explanations for asymmetrical patterns found in early word recognition. We systematically investigated the use of two types of phonological contrasts in toddlers' word recognition: manner and place of articulation. Ninety-six Dutch 18- and 25-month-olds were tested in a mispronunciation detection task. We show that 18-month-olds are sensitive to changes from fricative to stop, but not from stop to fricative, while 25-month-olds are able to detect changes in both directions. Confirming earlier findings on perceptual asymmetries, we find a similar asymmetrical pattern for mispronunciations involving labials and coronals at 18 months of age. We argue that the observed asymmetries reflect the nature of phonological representations used for word recognition at different stages of development.

Individual Differences in the Acquisition of a Complex L2 Phonology: A Training Study

Many learners of a foreign language (L2) struggle to correctly pronounce newly learned speech sounds, yet many others achieve this with apparent ease. Here we explored how a training study of learning complex consonant clusters at the very onset of L2 acquisition can inform us about L2 learning in general and individual differences in particular. To this end, adult Dutch native speakers were trained on Slovak words with complex consonant clusters (e.g., pstruh/pstrux/“trout”, štvrt'/ʃtvrc/“quarter”) using auditory and orthographic input. In the same session following training, participants were tested on a battery of L2 perception and production tasks. The battery of L2 tests was repeated twice more with 1 week between sessions. In the first session, an additional battery of control tests was used to test participants’ native language (L1) skills. Overall, in line with some previous research, participants showed only weak learning effects across the L2 perception tasks. However, there were considerable individual differences across all L2 tasks, which remained stable across sessions. Only two participants showed overall high L2 production performance that fell within 2 standard deviations of the mean ratings obtained for an L1 speaker. The mispronunciation detection task was the only perception task which significantly predicted production performance in the final session. We conclude by discussing several recommendations for future L2 learning studies.

Learning novel words: Detail and vulnerability of initial representations for children with specific language impairment and typically developing peers

This study examines the phonological representations that children with specific language impairment (SLI) and typically developing peers (TD) have during the initial process of word learning. The goals of this study were to determine if children with SLI attended to different components of words than peers, and whether they were more vulnerable to interference than peers. Forty 7- and 8-year-old children, half with SLI, took part in a fast mapping, word learning task. In addition to producing the word, there was a mispronunciation detection task that included mispronunciations of the target word in the initial position, final position or that modified the word's syllable structure. Children with SLI showed a different learning profile than peers, demonstrating stronger representations of the word-initial phonemes, but less information about word-final phonemes. They were more prone to interference overall, but especially from word-final foils. Children with SLI did not demonstrate less-defined phonological representations, but did attend to different features than TD children, perhaps in an attempt to compensate for problems learning longer words. The greatest weakness of children with SLI appears to be their susceptibility to interference, particularly for word-final information.Learning outcomes: Readers will be able to: (1) explain what children attend to when learning new words; (2) state the pattern of recognition and production performance for both children with SLI and their typical language peers; and (3) identify specific parts of novel words that are most susceptible to interference in children with SLI.

Developmental complexity of the stimuli included in mispronunciation detection tasks

Phonological representations are important for speech and literacy development. Mispronunciation detection tasks have been proposed as an appropriate measure of phonological representations for children with speech disorder. There has been limited analysis, however, of the developmental complexity of task stimuli. Further, the tasks have not been used widely with typical populations. The study aimed to examine the developmental progression of children's performance on a mispronunciation detection task, to evaluate the complexity of the task's stimuli, and to analyse the association between task performance and other skills important for literacy success. A cross-sectional design was used to compare the mispronunciation detection performance of monolingual children within mainstream classrooms aged 4;0-4;5 (n = 26), 4;6-5;0 (n = 49), and 5;1-5;6 (n = 64). Comparison of the complexity of vowel mismatches, single consonant mismatches, consonant deletion mismatches, and consonant transposition mismatches was conducted. Children in the youngest age group were outperformed by the older age groups in the phonological representation task. Fine-grained mismatches were more difficult to detect than coarse-grained mismatches. There was a trend for vowel substitutions to be the most difficult mismatch to detect. Performance in the mispronunciation detection task was moderately correlated with the children's receptive vocabulary, speech, phonological awareness, and letter knowledge skills. Mismatch type must be taken into account when designing mispronunciation detection tasks. Access to segmental phonological representations is related to speech, language, and letter knowledge in children from mainstream classrooms.

The effects of linguistic experience on the perception of [h

Languages with onset‐[h] are thought to be more likely to develop coda‐[h] than languages with no [h] at all [D. Silverman, Phasing and Recoverability (Garland, New York, 1997)]. It is therefore expected that speakers of languages with onset‐[h] should be more likely to perceive coda‐[h] than speakers of a language with no [h]. The goal of this study is to test this hypothesis. Speakers of French (a language with no [h]) and English (which allows onset‐[h]) were instructed to monitor for [h] in strings of nonce words with [h] in onset or coda positions. If English speakers perform significantly better than French speakers on coda‐[h] perception, then the hypothesis is supported. Subjects also participated in a mispronunciation detection task, where they monitored for errors in words of their language. The stimuli were common English and French monosyllabic words ending in [s, f, ∫], with the fricatives spliced and replaced with [h], keeping the formant transitions intact. The stimuli were randomly placed in a string of native words with no contextual cues. If the hypothesis is supported, findings should show faster and more accurate mispronunciation detection for English speakers than French speakers, suggesting that English speakers are more likely to perceive coda‐[h].

Testing the protracted lexical restructuring hypothesis: The effects of position and acoustic–phonetic clarity on sensitivity to mispronunciations in children and adults

Although developmental increases in the size of the position effect within a mispronunciation detection task have been interpreted as consistent with a view of the lexical restructuring process as protracted, the position effect itself might not be reliable. The current research examined the effects of position and clarity of acoustic–phonetic information on sensitivity to mispronounced onsets in 5- and 6-year-olds and adults. Both children and adults showed a position effect only when mispronunciations also differed in the amount of relevant acoustic–phonetic information. Adults’ sensitivity to mispronounced second-syllable onsets also reflected the availability of acoustic–phonetic information. The implications of these findings are discussed in relation to the lexical restructuring hypothesis.

Nature of phonological delay in children with specific language impairment

This study investigated the nature of phonological delay in a group of children with specific language impairment. It was asked whether phonological errors in this group of children were generated by a slow but normal language learning process or whether they reflected a selective impairment in some representations that enhance normal acquisition and use of a language phonology. A group of 10 children with SLI (mean age = 5.1) was compared with three groups of normal children who were matched in age (age control group, mean age = 5.1), in sentence comprehension and recalling (grammar control group, mean age = 3.7), or who exhibited a phonological performance lower than the age average (group with low phonological performance, mean age = 4.4). The four groups of children were assessed in terms of: (1) responses to a mispronunciation detection task; and (2) error profiles with complex and simple syllabic structures. Performance on the mispronunciation detection task showed that the group with SLI could distinguish a target lexical item from acoustic non-word stimuli that were highly similar to it in terms of phonetic characteristics. An analysis of overall error rate at this task showed, however, that four children with SLI had a much lower performance than normal children of the same age, even when the auditory stimuli were tokens of the target word, or non-words that were phonetically different from the target. A difficulty in coordinating vocal actions in an articulatory plan accounted for error profiles with simple syllabic structures both for some children with SLI and normal children with phonological performance lower than the age average. A severe difficulty with representing complex syllabic structures was a homogeneous characteristic of the group with SLI and worked as the main indicator of impaired, rather than simply slow, phonological development.

Nature of phonological delay in children with specific language impairment

This study investigated the nature of phonological delay in a group of children with specific language impairment. It was asked whether phonological errors in this group of children were generated by a slow but normal language learning process or whether they reflected a selective impairment in some representations that enhance normal acquisition and use of a language phonology. A group of 10 children with SLI (mean age=5,1) was compared with three groups of normal children who were matched in age (age control group, mean age=5,1), in sentence comprehension and recalling (grammar control group, mean age= 3,7), or who exhibited a phonological performance lower than the age average (group with low phonological performance, mean age=4,4). The four groups of children were assessed in terms of: (1) responses to a mispronunciation detection task; and (2) error profiles with complex and simple syllabic structures. Performance on the mispronunciation detection task showed that the group with SLI could distinguish...

The growth of lexical constraints on spoken word recognition

In this study, we examined the influence of various sources of constraint on spoken word recognition in a mispronunciation-detection task. Five- and 8-year-olds and adults were presented with words (intact or with word-initial or noninitial errors) from three different age-of-acquisition categories. "Intact" and "mispronounced" responses were collected for isolated words with or without a picture referent (Experiment 1) and for words in constraining or unconstraining sentences (Experiment 2). Some evidence for differential attention to word-initial as opposed to noninitial acoustic-phonetic information (and thus the influence of sequential lexical constraints on recognition) was apparent in young children's and adults' response criteria and in older children's and adults' reaction times. A more marked finding, however, was the variation in subjects' performance, according to several measures, with age and lexical familiarity (defined according to adults' subjective age-of-acquisition estimates). Children's strategies for responding to familiar and unfamiliar words in different contexts are discussed.

Processing interactions and lexical access during word recognition in continuous speech

The interactions, during word-recognition in continuous speech, between the bottom-up analyses of the input and different forms of internally generated top-down constraint, were investigated using a shadowing task and a mispronunciation detection task (in the detection task the subject saw a text of the original passage as he listened to it). The listener's dependence on bottom-up analyses in the shadowing task, as measured by the number of fluent restorations of mispronounced words, was found to vary as a function of the syllable position of the mispronunciation within the word and of the contextual constraints on the word as a whole. In the detection task only syllable position effects were obtained. The results, discussed in conjunction with earlier research, were found to be inconsistent with either the logogen model of word-recognition or an autonomous search model. Instead, an active direct access model is proposed, in which top-down processing constraints interact directly with bottom-up information to produce the primary lexical interpretation of the acoustic-phonetic input.