Relationship between the target word form and children's productions: place of articulation in Consonant-Vowel-Consonant (C1VC2) words in American English.

The aim of the present study was to investigate relationships between characteristics of children's target words and their actual productions during the single-word period in American English. Word productions in spontaneous and functional speech from 18 children acquiring American English were analyzed. Consonant sequences in 3,328 consonant-vowel-consonant (C1VC2) target words were analyzed in terms of global place of articulation (labials, coronals, and dorsals). Children's actual productions of place sequences were compared between target words containing repeated place sequences (e.g., mom, map, dad, not) and target words containing variegated place sequences (e.g., mat, dog, cat, nap). Overall, when the target word contained two consonants at the same global place of articulation (e.g., labial-labial, map; coronal-coronal, not), approximately 50% of children's actual productions matched consonant place characteristics. Conversely, when the target word consisted of variegated place sequences (e.g., mat, dog, cat, nap), only about 20% of the productions matched the target consonant sequences. These results suggest that children's actual productions are influenced by their own production abilities as well as by the phonetic forms of target words.

An acoustic analysis of American English liquids by adults and children: Native English speakers and native Japanese speakers of English.

This study investigated acoustic characteristics of American English liquids produced by native English (NE) and native Japanese (NJ) speakers reported in Aoyama, Flege, Guion, Akahane-Yamada, and Yamada [(2004). J. Phonetics 32, 233-250]. For a larger longitudinal study, the data were collected twice to investigate the acquisition of American English by the NJ speakers (Time 1, Time 2). Aoyama, Flege, Guion, Akahane-Yamada, and Yamada [(2004). J. Phonetics 32, 233-250] evaluated productions of /l/ and /ɹ/ in the NE and NJ adults and children (16 participants each) using NE speakers' perceptual judgments and showed that the NJ children's production of /ɹ/ improved from Time 1 to Time 2. In the current study, four acoustic parameters (duration, F1, F2, and F3) were measured in 256 tokens each of English /l/ and /ɹ/. Results showed that some acoustic parameters, such as F2, changed from Time 1 to Time 2 in the NJ speakers' productions, indicating improvements. However, the NJ speakers' productions were different from the NE speakers' productions in almost all acoustic parameters at both Time 1 and Time 2. Results suggest that the improvements in the NJ children's productions of /ɹ/ reported in Aoyama, Flege, Guion, Akahane-Yamada, and Yamada [(2004). J. Phonetics 32, 233-250] were due to a combination of changes, not due to a change in one acoustic parameter such as F3 in /ɹ/.

Non-adjacent consonant sequence patterns in English target words during the first-word period.

The goal of this study was to investigate non-adjacent consonant sequence patterns in target words during the first-word period in infants learning American English. In the spontaneous speech of eighteen participants, target words with a Consonant-Vowel-Consonant (C1VC2) shape were analyzed. Target words were grouped into nine types, categorized by place of articulation (labial, coronal, dorsal) of initial and final consonants (e.g. mom, labial-labial; mat, labial-coronal; dog, coronal-dorsal). The results indicated that some consonant sequences occurred much more frequently than others in early target words. The two most frequent types were coronal-coronal (e.g. dad) and labial-coronal (e.g. mat). The least frequent type was dorsal-dorsal (e.g. cake). These patterns are consistent with phonotactic characteristics of English and infants' production capacities reported in previous studies. This study demonstrates that infants' expressive vocabularies reflect both ambient language characteristics and their own production capacities, at least for consonant sequences in C1VC2 word forms.

Bye-Bye Bunny: Place and Manner Sequences in Children's C1VC2V-Shaped Words.

PURPOSE: Place and manner of articulation in American English-learning children's salient consonant-vowel-consonant-vowel (C1VC2V) target words (e.g., baby, bunny, and cookie) were compared with their actual productions of these words. We hypothesized that target words with repeated place and/or manner characteristics in C1VC2V consonant sequences would be matched in children's actual productions more frequently than target words with variegated place and manner sequences. This hypothesis was based on a proposal that children use available production system capacities to produce salient word forms derived from perceptual input on those word forms. METHOD: Place and manner sequences were analyzed in 2,092 tokens of C1VC2V target words produced by 18 typically developing children in the single-word period. All data were from these children's spontaneous functional speech in a familiar speaking context. Both target word forms and actual child productions of those targets were analyzed. RESULTS: Results indicated that C1VC2V word target sequences predominantly consisted of repetitions in both place and manner of articulation (e.g., labial-labial, stop-stop). Targets with repetitions of consonant sequences were matched more frequently than targets with variegated sequences for both place and manner (e.g., labial-coronal, stop-nasal) in these children's actual productions. Results also indicated that C1VC2V target words beginning with a labial consonant (e.g., baby, bunny, and piggy) were matched in children's actual productions more frequently than words with coronal or dorsal consonant onsets (e.g., daddy and cookie). DISCUSSION: In C1VC2V word forms, occurring in early output, children's actual productions matched their target word sequences when the words consisted of repeated sequences in both place and manner. These results suggest that salient target words with repeated sequences may help children support increases in their repertoire of meaningful vocalizations during the transition from babbling to meaningful speech.

Relationships Between Acoustic Characteristics and Intelligibility Scores: A Reanalysis of Japanese Speakers' Productions of American English Liquids.

The primary purpose of this research report was to investigate the relationships between acoustic characteristics and perceived intelligibility for native Japanese speakers' productions of American English liquids. This report was based on a reanalysis of intelligibility scores and acoustic analyses that were reported in two previous studies. We examined which acoustic parameters were associated with higher perceived intelligibility scores for their productions of /l/ and /ɹ/ in American English, and whether Japanese speakers' productions of the two liquids were acoustically differentiated from each other. Results demonstrated that the second formant (F2) was strongly correlated with the perceived intelligibility scores for the Japanese adults' productions. Results also demonstrated that the Japanese adults' and children's productions of /l/ and /ɹ/ were indeed differentiated by some acoustic parameters including the third formant (F3). In addition, some changes occurred in the Japanese children's productions over the course of 1 year. Overall, the present report shows that Japanese speakers of American English may be making a distinction between /l/ and /ɹ/ in production, although the distinctions are made in a different way compared with native English speakers' productions. These findings have implications for setting realistic goals for improving intelligibility of English /l/ and /ɹ/ for Japanese speakers, as well as theoretical advancement of second-language speech learning.

Phonological changes during the transition from one-word to productive word combination.

We investigated developmental changes during the transition from one-word to two-word production, focusing on strategies to lengthen utterances phonologically and to control utterances suprasegmentally. We hypothesized that there is a period of reorganization at the onset of word combinations indicated by decreases in both filler syllables (Fillers) and final syllable lengthening (FSL). The data are from a visually impaired child (Seth) between 1; 6.21 and 1; 10.26. Seth produced many Fillers until 1; 9 when their number decreased for about two weeks after which they changed in nature. FSL was observed until 1; 8, but diminished at 1; 9. These two regressions coincide with the onset of word combination.

Speech Recognition in Noise in Adults and Children Who Speak English or Chinese as Their First Language.

BACKGROUND: Speech recognition of individuals who are listening to a nonnative language is significantly degraded in the presence of background noise and may be influenced by proficiency, age of acquisition, language experience, and daily use of the nonnative language. PURPOSE: The purpose of this study is to examine and compare speech recognition in noise performance across test conditions with varying signal-to-noise ratios (SNRs) as well as the presence of vocal and spatial cues in listeners who speak American English as a native language or Mandarin Chinese as a native language. Self-rated English proficiency and experience were collected for native Mandarin Chinese speakers to determine its relationship to performance on the test measures. RESEARCH DESIGN: A cross-sectional repeated measures design was used for the study. STUDY SAMPLE: Four groups of participants were included in the study. The adult groups consisted of 25 adults who speak native English and 25 adults who speak native Mandarin Chinese with English as an additional language. The pediatric groups consisted of 16 children who speak native English and 16 children who speak native Mandarin Chinese with English as an additional language. DATA COLLECTION AND ANALYSES: Percent correct speech recognition in noise was assessed at three SNRs (-3, 0, +3 dB) using the adult or pediatric versions of the AzBio sentence test. The Listening in Spatialized Noise-Sentence (LiSN-S) test was used to determine the effect of providing spatial and vocal cues on the speech recognition in noise performance of the groups of participants. The data for each age group and test measure were analyzed with a repeated measures analysis of variance. Correlation analyses were performed to examine relationships between English proficiency and experience on performance across the speech recognition test conditions. RESULTS: Analysis of the data from the adult or pediatric AzBio sentence test identified a significant effect of native language for adults but no significant effect for children. The higher SNRs yielded better performance for all listeners. On the LiSN-S test, results for the adult and pediatric groups were similar and showed significantly better performance for the native English speakers in every test condition. The demographic and language characteristics that most affected speech recognition performance across the test measures included the length of time the person lived in the United States, the age of English acquisition, the number of minutes per day English was spoken by the participant, and the self-rated English proficiency. CONCLUSIONS: The findings in this study highlight the importance and benefit of higher SNRs as well as the provision of vocal and spatial cues for improving speech recognition performance in noise of adult and pediatric listeners who speak Mandarin Chinese as a native language.

A one-year longitudinal study of English and Japanese vowel production by Japanese adults and children in an English-speaking setting.

The effect of age of acquisition on first- and second-language vowel production was investigated. Eight English vowels were produced by Native Japanese (NJ) adults and children as well as by age-matched Native English (NE) adults and children. Productions were recorded shortly after the NJ participants' arrival in the USA and then one year later. In agreement with previous investigations [Aoyama, et al., J. Phon. 32, 233-250 (2004)], children were able to learn more, leading to higher accuracy than adults in a year's time. Based on the spectral quality and duration comparisons, NJ adults had more accurate production at Time 1, but showed no improvement over time. The NJ children's productions, however, showed significant differences from the NE children's for English "new" vowels /ɪ/, /ε/, /ɑ/, /ʌ/ and /ʊ/ at Time 1, but produced all eight vowels in a native-like manner at Time 2. An examination of NJ speakers' productions of Japanese /i/, /a/, /u/ over time revealed significant changes for the NJ Child Group only. Japanese /i/ and /a/ showed changes in production that can be related to second language (L2) learning. The results suggest that L2 vowel production is affected importantly by age of acquisition and that there is a dynamic interaction, whereby the first and second language vowels affect each other.