Jae Yung Song

The development of articles in children's early Spanish: prosodic interactions between lexical and grammatical form

Studies of English and French show that children’s first articles are more likely to appear when they can be prosodified as part of a disyllabic foot (cf. Gerken, 1996; Demuth & Tremblay, 2008). However, preliminary studies of Spanish suggest that children’s first articles appear in larger prosodic structures, possibly due to the higher frequency of longer words. To assess this issue, this study examined longitudinal data from two Spanish 1- to 2-year-olds. As expected, both produced their early articles with monosyllabic and disyllabic nouns, rapidly expanding article use to trisyllabic nouns as well. The results suggest that the prosodic complexity of the lexicon plays an important role in the development of prosodic structure, providing the context for early prosodic licensing of grammatical morphemes.

The development of acoustic cues to coda contrasts in young children learning American English

Research on childrens speech perception and production suggests that consonant voicing and place contrasts may be acquired early in life, at least in word-onset position. However, little is known about the development of the acoustic correlates of later-acquired, word-final coda contrasts. This is of particular interest in languages like English where many grammatical morphemes are realized as codas. This study therefore examined how various non-spectral acoustic cues vary as a function of stop coda voicing (voiced vs. voiceless) and place (alveolar vs. velar) in the spontaneous speech of 6 American-English-speaking mother-child dyads. The results indicate that children as young as 1;6 exhibited many adult-like acoustic cues to voicing and place contrasts, including longer vowels and more frequent use of voice bar with voiced codas, and a greater number of bursts and longer post-release noise for velar codas. However, 1;6-year-olds overall exhibited longer durations and more frequent occurrence of these cues compared to mothers, with decreasing values by 2;6. Thus, English-speaking 1;6-year-olds already exhibit adult-like use of some of the cues to coda voicing and place, though implementation is not yet fully adult-like. Physiological and contextual correlates of these findings are discussed.

The effects of coarticulation and morphological complexity on the production of English coda clusters: Acoustic and articulatory evidence from 2-year-olds and adults using ultrasound

Most studies of phonological development have explored the acquisition of segments, syllables and words using perceptual/transcription methods. Less is known about the articulatory aspects of early speech, or the development of articulatory-acoustic mapping. Recent research on adult speech finds that coarticulation effects are evidenced in both the acoustics and the articulatory gestures, and suggests tighter coarticulation and less variability for monomorphemic compared to polymorphemic segment sequences. The present study explored phonological context and morphological effects in the speech of five adults and five 2-year-olds, combining acoustic and articulatory analysis from ultrasound recordings. The results show that coarticulation effects are found in the word-final consonant cluster (box) for both adults and children. For children, these were evidenced only in the articulatory data. In addition, both age groups showed differences in tongue height between the monomorphemic (box) and bimorphemic (rocks) clusters, suggesting a possible morphological effect. These findings confirm that ultrasound methods can be successfully employed to explore aspects of early gestural development in children as young as 2, and raise many questions regarding the nature of speech planning processes as a function of lexical versus morphological form.

Durational cues to fricative codas in 2-year-olds' American English: Voicing and morphemic factors

In the process of phonological development, fricatives are generally assumed to be later acquired than stops. However, most of the observational work on which this claim is based has concerned itself with word-initial onset consonants; little is known about how and when fricatives are mastered in word-final coda position (e.g., nose). This is all the more critical in a language like English, where word-final fricatives often carry important morphological information (e.g., toes, goes). This study examines the development of duration cues to the voicing feature contrast in coda fricatives, using longitudinal spontaneous speech data from CVC words (e.g., noise vs face) produced by three children (1;6-2;6 years) and six mothers. Results show that the children were remarkably adult-like in the use of duration cues to voicing contrasts in fricatives even in this early age range. Furthermore the children, like the mothers, had longer frication noise durations for morphemic compared to non-morphemic fricatives (e.g., toes vs nose) when these segments occurred in utterance-final position. These results suggest that although childrens fricatives tend to be overall longer and more voiced compared to those of adults, the voicing and morphological contrasts for fricative codas are acquired early in production.

The role of hypercorrection in the acquisition of L2 phonemic contrasts

This article reports empirical findings from an ongoing investigation into the acquisition of second-language (L2) phonemic contrasts. Specifically, we consider the status and role of the phenomenon of hypercorrection in the various stages through which L2 learners develop and internalize a target language (TL) contrast. We adopt the prevailing view in both sociolinguistics and second language acquisition studies that hypercorrection results from a certain amount of linguistic insecurity on the part of the speaker. Based on 53 Korean speakers’ production of English target phonemes, we conclude that a series of hypercorrection errors may well represent the final stage in the acquisition of a contrast, and further, that in order for hypercorrection to occur, there must be a formal connection between the TL contrast being acquired and the phonological structure of the learner’s native language.

Development of phonetic variants (allophones) in 2-year-olds learning American English: A study of alveolar stop /t, d/ codas

Abstract This study examined the emergence of the phonetic variants (often called allophones) of alveolar phonemes in the speech production of 2-year-olds. Our specific question was: Does the child start by producing a “canonical” form of a phoneme (e.g., /t/ with a clear closure and a release burst), only later learning to produce its other phonetic variants (e.g., unreleased stop, flap, and glottal stop)? Or, does the child start by producing the appropriate phonetic variants in the appropriate contexts and only later learn that they are phonetic variants of the same phoneme? In order to address this question, we investigated the production of three phonetic variants (unreleased stop, flap, and glottal stop) of the alveolar stop codas /t, d/ in the spontaneous speech of 6 American-English-speaking mother–child dyads, using both acoustic and perceptual coding. The results showed that 2-year-old children produced all three variants significantly less often than their mothers, and produced acoustic cues to canonical /t, d/ more often. This supports the view that young children start out by producing a fully articulated canonical variant of a phoneme in contexts where an adult would produce non-canonical forms. The implications of these findings for early phonological representations are discussed.

Patterns of development in stop‐release cues to coda contrasts in American‐English‐speaking 2‐year‐olds.

A distinctive characteristic of early speech is “exaggerated” release of stop consonants including multiple bursts and heavy post‐release noise [Imbrie (2005)]. This study provides an in‐depth investigation of changes in the acoustic characteristics of stop coda release from 1;6 to 2;6 years, focusing on their interaction with emerging linguistic contrasts. We examined how various non‐spectral coda‐release‐related cues, such as the presence and duration of post‐release noise, varied with coda voicing and place (alveolar versus velar) in spontaneous speech from six American‐English‐speaking mother‐child dyads. Starting as early as 1;6, children produced many of the same types of correlates of voicing and place as adults did, but they exhibited more frequent occurrences and longer durations of these cues compared to mothers; this exaggeration decreased by 2;6. In utterance‐medial position, where the decrease was particularly striking, it occurred in a selective, stepwise fashion rather than simultaneously i...

Acoustic cues to stop coda voicing contrasts in 1 to 2‐year‐olds’ American English.

One limitation in understanding the mechanisms underlying children’s variable productions has been the reliance on perception‐based segmental transcription. This raises the possibility that children may make covert, acoustic distinctions that are not perceived by the transcriber. Shattuck‐Hufnagel et al. [S. Shattuck‐Hufnagel, K. Demuth, H. Hanson & S. Stevens, submitted] investigated this issue employing Stevens’ [K. N. Stevens, J. Acoust. Soc. Am. 111, 1872–1891 (2002)] feature‐based acoustic model of perception/production. They found that 2,6–3,6‐year‐olds exhibited systematic acoustic cues to coda voicing contrasts (e.g., dog versus duck): voice‐bar was more likely to precede voiced codas, whereas vowel glottalization was more likely to precede voiceless codas. The present study extended this investigation to velar codas in three 1,6–2,6‐year‐olds and their mothers, showing similar results: both exhibited more use of voice‐bar before voiced compared to voiceless codas. For mothers, the duration of voi...

The use of ultrasound in the study of articulatory properties of vowels in clear speech

ABSTRACT Although the acoustic properties of clear speech have been extensively studied, its underlying articulatory details have not been well understood. The purpose of the present study is twofold: To examine the specific articulatory processes of clear speech using ultrasound and to investigate whether and how the type of listener (hard of hearing, normal hearing) and the lexical property of words (frequency) interact in the production of clear speech. To this end, we examined productions of /ɑ/, /æ/ and /u/ from 16 speakers of US English. Overall, our ultrasound results suggested that the tongue’s highest point moved in a direction that exaggerated the three vowels’ phonological features, resulting in an expanded articulatory vowel space for the hard-of-hearing listener and low-frequency words. No interaction was found between the listener and word frequency, suggesting that the effects of word frequency hold constant across the two types of listeners.