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Previous work on children's acquisition of complex sequences points to a tendency for affricates to be acquired before clusters, but there is no clear evidence of a difference in order of acquisition between clusters with /s/ that violate the Sonority Sequencing Principle (SSP), such as /s/ followed by stop in onset position, and other clusters that obey the SSP. One problem with studies that have compared the acquisition of SSP-obeying and SSP-violating clusters is that the component sounds in the two types of sequences were different. This paper examines the acquisition of initial /s/-stop and stop-/s/ sequences by sixty Greek children aged 2 through 5 years. Results showed greater accuracy for the /s/-stop relative to the stop-/s/ sequences, but no difference in accuracy between /ts/, which is usually analyzed as an affricate in Greek, and the other stop-/s/ sequences. Moreover, errors for the /s/-stop sequences and /ts/ primarily involved stop substitutions, whereas errors for /ps/ and /ks/ were more variable and often involved fricative substitutions, a pattern which may have a perceptual explanation. Finally, /ts/ showed a distinct temporal pattern relative to the stop-/s/ clusters /ps/ and /ks/, similar to what has been reported for productions of Greek adults. (Contains 5 figures and 6 tables.)

We applaud Stoel-Gammon's (this issue) call for a more comprehensive account of the relationship between lexicon and phonology, and we strongly endorse her suggestions for future research. However, we think that it will not be enough simply to integrate findings and methods from the adult-centered and child-centered literatures. Both of these literatures suggest that we need to rethink standard assumptions about what phonological representations are and how they emerge to support the very large vocabularies that speakers develop over the course of a lifetime. Our commentary focuses on three themes relevant to this reconceptualization.

This article honours Adele Miccio's life work by reflecting on the utility of phonetic transcription. The first section reviews the literature on cases where children whose speech appears to neutralize a contrast in the adult language are found on closer examination to produce a contrast ("covert contrast"). This study presents evidence from a new series of perception studies that covert contrast may be far more prevalent in children's speech than existing studies would suggest. The second section presents the results of a new study designed to examine whether naive listeners' perception of children's /s/ and /[theta]/ productions can be changed experimentally when they are led to believe that the children who produced the sounds were older or younger. Here, it is shown that, under the right circumstances, adults report more tokens of /[theta]/ to be accurate productions of /s/ when they believe a talker to be an older child than when they believe the talker to be younger. This finding suggests that auditory information alone cannot be the sole basis for judging the accuracy of a sound. The final section presents recommendations for supplementing phonetic transcription with other measures, to gain a fuller picture of children's production abilities. (Contains 2 tables and 3 figures.)

Consonant mastery is one of the most widely used metrics of typical phonological acquisition and of phonological disorder. Two fundamental methodological questions concerning research on consonant acquisition are (1) how to elicit a representative sample of productions and (2) how to analyse this sample once it has been collected. This paper addresses these two questions by reviewing relevant aspects of experience in evaluating word-initial consonant accuracy from transcriptions of isolated-word productions elicited from 2- and 3-year-olds learning four different first languages representing a telling range of consonant systems (English, Cantonese, Greek, Japanese). It is suggested that both researchers and clinicians should consider a number of different item-related factors, such as phonotactic probability and word length, when constructing word lists to elicit consonant productions from young children. This study also proposes that transcription should be supplemented by acoustic analysis and the perceptual judgements of naive listeners. (Contains 4 figures.)

This article discusses 4 types of phonological knowledge: knowledge of the acoustic and perceptual characteristics of speech sounds (perceptual knowledge), knowledge of the articulatory characteristics of speech sounds (articulatory knowledge), higher level knowledge of the ways that words can be divided into sounds and related phonotactic constraints on how sounds can be combined into words (higher level phonological knowledge), and knowledge of the ways that variation in pronunciation can be used to convey social identity (social-indexical knowledge). The first section of the article discusses the nature of these types of knowledge in adults. The second describes how they develop in children with typical language development. The third section outlines how different types of knowledge may be compromised in children with functional speech-sound impairments. Together these 5 sections serve as a review for practicing clinicians of the types of phonological knowledge that underlie accurate and fluent speech production.

Adults' performance on a variety of tasks suggests that phonological processing of nonwords is grounded in generalizations about sublexical patterns over all known words. A small body of research suggests that children's phonological acquisition is similarly based on generalizations over the lexicon. To test this account, production accuracy and fluency were examined in nonword repetitions by 104 children and 22 adults. Stimuli were 22 pairs of nonwords, in which one nonword contained a low-frequency or unattested two-phoneme sequence and the other contained a high-frequency sequence. For a subset of these nonword pairs, segment durations were measured. The same sound was produced with a longer duration (less fluently) when it appeared in a low-frequency sequence, as compared to a high-frequency sequence. Low-frequency sequences were also repeated with lower accuracy than high-frequency sequences. Moreover, children with smaller vocabularies showed a larger influence of frequency on accuracy than children with larger vocabularies. Taken together, these results provide support for a model of phonological acquisition in which knowledge of sublexical units emerges from generalizations made over lexical items.KEY WORDS: phonological development, lexical development, phonotactic probability

This study investigated two aspects of non-symbolic phonological knowledge (knowledge of the acoustic/perceptual space and of the articulatory/production space) in six preschool-age children with phonological disorders and six typically developing age peers. Results suggest that phonological knowledge is multifaceted, and that seemingly categorical deficits at one level can be linked to less robust representations at other levels. (Author/DB)

Methods from automatic speech recognition (ASR), such as segmentation and forced alignment, have facilitated the rapid annotation and analysis of very large adult speech databases and databases of caregiver–infant interaction, enabling advances in speech science that were unimaginable just a few decades ago. This paper centers on two main problems that must be addressed in order to have analogous resources for developing and exploiting databases of young children’s speech. The first problem is to understand and appreciate the differences between adult and child speech that cause ASR models developed for adult speech to fail when applied to child speech. These differences include the fact that children’s vocal tracts are smaller than those of adult males and also changing rapidly in size and shape over the course of development, leading to between-talker variability across age groups that dwarfs the between-talker differences between adult men and women. Moreover, children do not achieve fully adult-like speech motor control until they are young adults, and their vocabularies and phonological proficiency are developing as well, leading to considerably more within-talker variability as well as more between-talker variability. The second problem then is to determine what annotation schemas and analysis techniques can most usefully capture relevant aspects of this variability. Indeed, standard acoustic characterizations applied to child speech reveal that adult-centered annotation schemas fail to capture phenomena such as the emergence of covert contrasts in children’s developing phonological systems, while also revealing children’s nonuniform progression toward community speech norms as they acquire the phonological systems of their native languages. Both problems point to the need for more basic research into the growth and development of the articulatory system (as well as of the lexicon and phonological system) that is oriented explicitly toward the construction of age-appropriate computational models. [ABSTRACT FROM AUTHOR]

Purpose: Four measures of children's developing robustness of phonological contrast were compared to see how they correlated with age, vocabulary size, and adult listeners' correctness ratings. Method: Word-initial sibilant fricative productions from eighty-one 2- to 5-year-old children and 20 adults were phonetically transcribed and acoustically analyzed. Four measures of robustness of contrast were calculated for each speaker on the basis of the centroid frequency measured from each fricative token. Productions that were transcribed as correct from different children were then used as stimuli in a perception experiment in which adult listeners rated the goodness of each production. Results: Results showed that the degree of category overlap, quantified as the percentage of a child's productions whose category could be correctly predicted from the output of a mixed-effects logistic regression model, was the measure that correlated best with listeners' goodness judgments. Conclusions: Even when children's productions have been transcribed as correct, adult listeners are sensitive to within-category variation quantified by the child's degree of category overlap. Further research is needed to explore the relationship between the age of a child and adults' sensitivity to different types of within-category variation in children's speech. [ABSTRACT FROM AUTHOR]

This paper examines whether data from a large cross-linguistic corpus of adult and child productions can be used to support an assumed corollary of the Neogrammarian distinction between two types of phonological change. The first type is regular sound change, which is assumed to be incremental and so should show continuity between phonological development and the age-related variation observed in the speech community undergoing the change. The second type is dialect borrowing, which could show an abrupt discontinuity between developmental patterns before and after the socio-historical circumstances that instigate it. We examine the acquisition of two contrasts: the Seoul Korean contrast between lax and aspirated stops which is undergoing regular sound change, and the standard Mandarin contrast between retroflex and dental sibilants which has been borrowed recently into the Sōngyuán dialect. Acquisition of the different contrasts patterns as predicted from the assumed differences between continuous regular sound change and potentially abrupt dialect borrowing. However, there are substantial gaps in our understanding both of the extent of cross-cultural variability in language socialization and of how this might affect the mechanisms of phonological change that must be addressed before we can fully understand the relationship between the time courses of the two. [ABSTRACT FROM AUTHOR]

Abstract: The age at which children master adult-like voiced stops can generally be predicted by voice onset time (VOT): stops with optional short lag are early, those with obligatory lead are late. However, Japanese voiced stops are late despite having a short lag variant, whereas Greek voiced stops are early despite having consistent voicing lead. This cross-sectional study examines the acoustics of word-initial stops produced by English-, Japanese-, and Greek-speaking children aged 2–5, to investigate how these seemingly exceptional mastery patterns relate to use of other phonetic correlates. Productions were analyzed for VOT, f0 and spectral tilt (H1−H2) in Japanese and English, and for amplitude trajectory in Greek and Japanese. Japanese voiceless stops have intermediate lag VOT values, so other “secondary” cues are needed to differentiate them from the voiced short lag VOT variant. Greek voiced stops are optionally prenasalized, and the amplitude trajectory for the voice bar during closure suggests that younger children use a greater degree of nasal venting to create the aerodynamic conditions necessary for voicing lead. Taken together, the findings suggest that VOT must be supplemented by measurements of other language-specific acoustic properties to explain the mastery pattern of voiced stops in some languages. [Copyright &y& Elsevier]

Previous work on children’s acquisition of complex sequences points to a tendency for affricates to be acquired before clusters, but there is no clear evidence of a difference in order of acquisition between clusters with /s/ that violate the Sonority Sequencing Principle (SSP), such as /s/ followed by stop in onset position, and other clusters that obey the SSP. One problem with studies that have compared the acquisition of SSP-obeying and SSP-violating clusters is that the component sounds in the two types of sequences were different. This paper examines the acquisition of initial /s/-stop and stop-/s/ sequences by sixty Greek children aged 2 through 5 years. Results showed greater accuracy for the /s/-stop relative to the stop-/s/ sequences, but no difference in accuracy between /ts/, which is usually analyzed as an affricate in Greek, and the other stop-/s/ sequences. Moreover, errors for the /s/-stop sequences and /ts/ primarily involved stop substitutions, whereas errors for /ps/ and /ks/ were more variable and often involved fricative substitutions, a pattern which may have a perceptual explanation. Finally, /ts/ showed a distinct temporal pattern relative to the stop-/s/ clusters /ps/ and /ks/, similar to what has been reported for productions of Greek adults. [ABSTRACT FROM PUBLISHER]

Background: Receptive vocabulary is an important measure for language evaluations. Therefore, norm-referenced receptive vocabulary tests are widely used in several languages. However, a receptive vocabulary test has not yet been normed for Modern Greek. Aims: To adapt an American English vocabulary test, the Receptive One-Word Picture Vocabulary Test-II (ROWPVT-II), for Modern Greek for use with Greek-speaking preschool children. Methods & Procedures: The list of 170 English words on ROWPVT-II was adapted by (1) developing two lists (A and B) of Greek words that would match either the target English word or another concept corresponding to one of the pictured objects in the four-picture array; and (2) determining a developmental order for the chosen Greek words for preschool-aged children. For the first task, adult word frequency measures were used to select the words for the Greek wordlist. For the second task, 427 children, 225 boys and 202 girls, ranging in age from 2;0 years to 5;11 years, were recruited from urban and suburban areas of Greece. A pilot study of the two word lists was performed with the aim of comparing an equal number of list A and list B responses for each age group and deriving a new developmental list order. Outcomes & Results: The relative difficulty of each Greek word item, that is, its accuracy score, was calculated by taking the average proportion of correct responses across ages for that word. Subsequently, the word accuracy scores in the two lists were compared via regression analysis, which yielded a highly significant relationship ( R2= 0.97; p < 0.0001) and a few outlier pairs (via residuals). Further analysis used the original relative ranking order along with the derived ranking order from the average accuracy scores of the two lists in order to determine which word item from the two lists was a better fit. Finally, new starting levels (basals) were established for preschool ages. Conclusions & Implications: The revised word list can serve as the basis for adapting a receptive vocabulary test for Greek preschool-aged children. Further steps need to be taken when testing larger numbers of 2;0 to 5;11-year-old children on the revised word list for determination of norms. This effort will facilitate early identification and remediation of language disorders in Modern Greek-speaking children. [ABSTRACT FROM AUTHOR]

When they first begin to talk, children show characteristic consonant errors, which are often described in terms that recall Neogrammarian sound change. For example, a Japanese child's production of the word kimono might be transcribed with an initial postalveolar affricate, as in typical velar-softening sound changes. Broad-stroke reviews of errors list striking commonalities across children acquiring different languages, whereas quantitative studies reveal enormous variability across children, some of which seems related to differences in consonant frequencies across different lexicons. This paper asks whether the appearance of commonalities across children acquiring different languages might be reconciled with the observed variability by referring to the ways in which sound change might affect frequencies in the lexicon. Correlational analyses were used to assess relationships between consonant accuracy in a database of recordings of toddlers acquiring Cantonese, English, Greek, or Japanese and two measures of consonant frequency: one specific to the lexicon being acquired, the other an average frequency calculated for the other three languages. Results showed generally positive trends, although the strength of the trends differed across measures and across languages. Many outliers in plots depicting the relationships suggested historical contingencies that have conspired to make for unexpected paths, much as in biological evolution. [ABSTRACT FROM AUTHOR]

This article honours Adele Miccio's life work by reflecting on the utility of phonetic transcription. The first section reviews the literature on cases where children whose speech appears to neutralize a contrast in the adult language are found on closer examination to produce a contrast ( covert contrast). This study presents evidence from a new series of perception studies that covert contrast may be far more prevalent in children's speech than existing studies would suggest. The second section presents the results of a new study designed to examine whether naïve listeners' perception of children's /s/ and /θ/ productions can be changed experimentally when they are led to believe that the children who produced the sounds were older or younger. Here, it is shown that, under the right circumstances, adults report more tokens of /θ/ to be accurate productions of /s/ when they believe a talker to be an older child than when they believe the talker to be younger. This finding suggests that auditory information alone cannot be the sole basis for judging the accuracy of a sound. The final section presents recommendations for supplementing phonetic transcription with other measures, to gain a fuller picture of children's production abilities. [ABSTRACT FROM AUTHOR]