Assessing implicit phonological knowledge through accent imitation

The present study aims to investigate, through acoustic analysis, the acquisition of voicing contrast in Hungarian word-initial bilabial and alveolar stops (p/b and t/d) produced by 15 children with primary language disorders between 5;6 and 7;7 years of age. Data collection was based on a picture-naming task involving at least four different pictures for each segment tested. The elicited data were audio-recorded and then evaluated in terms of the proportion of pre-voiced stops per target category, the duration of voice onset time (VOT), and the presence of other phonetic features. The results revealed that, while all target voiceless stops are produced without pre-voicing, there is a bimodal distribution of VOTs for target voiced categories. Regarding the duration of VOTs, accurate realisations show average VOTs of immature values, and no sub-phonemic level differences were revealed in the distribution of VOTs for inaccurate realisations. Furthermore, voiceless realisations present frequently double/multiple release bursts. Findings are discussed in relation to a study on VOT distribution in the speech of typically developing children and to suggestions for further investigations.

Previous research indicates that talkers differ in phonetically relevant properties of speech, including voice-onset-time (VOT) in word-initial stop consonants; some talkers have characteristically shorter VOTs than others. Previous research also indicates that VOT is robustly affected by contextual influences, including speaking rate and place of articulation. This paper examines whether these contextual influences on VOT are themselves talker-specific. Many tokens of alveolar ti (experiment 1) or labial pi and velar ki (experiment 2) were elicited from talkers across a range of rates. VOT and vowel duration (a metric of rate) were measured for each token. Hierarchical linear modeling analyses showed that (1) VOT increased as rate decreased for all talkers, but the magnitude of the increase varied significantly across talkers; thus the effect of rate on VOT was talker-specific; (2) the talker-specific effect of rate was stable across a change in place of articulation; and (3) for all talkers VOTs were shorter for labial than velar stops, and there was no significant variability in the magnitude of this displacement across talkers; thus the effect of place on VOT was not talker-specific. The implications of these findings for how listeners might accommodate talker differences in VOT during speech perception are discussed.

Investigations of the phonetics of infant-directed speech (IDS) have mainly focused on prosodic aspects, showing extreme values or overspecifications in comparison to adult-directed speech (ADS). On the other hand, studies of segmental properties, especially consonantal ones, are very rare. The lack of knowledge of phonetic characteristics of the infant’s speech input is problematic, considering that the infant’s perceptual development seems to be attuned towards properties in the ambient language, as suggested by infant perception experiments. In the present study voice onset time (VOT) was measured in Swedish mothers’ IDS and in their ADS. VOT was significantly shorter in IDS than in ADS in both voiced and voiceless stops. The impact of stress was very clear in both IDS and ADS, showing significantly longer VOT in stressed positions as compared to the unstressed. The results are discussed in a framework assuming a differential weighting system of different phonetic aspects such as prosodic, consonantal and vocalic, as a function of infant development.

Aims and objectives: This study examines how cognate status and elicitation tasks affect Voice Onset Time (VOT) production in advanced Japanese-English bilinguals. It investigates whether bilinguals exhibit phonetic cross-linguistic influence in both their first (L1) and second (L2) languages and compares their L2 productions to a native English baseline to assess phonetic attainment. Design/methodology/approach: VOT data for word-initial /k/ were collected from 28 advanced Japanese-English bilinguals and a control group of 6 native English speakers. Participants produced cognate and non-cognate words in both Japanese (bilinguals only) and English using two tasks: picture naming and sentence reading. Data and analysis: A total of 2016 tokens from the bilinguals and 216 from the native speakers were acoustically analyzed. Mean VOT values were submitted to a mixed-design ANOVA to compare the groups’ English productions and a repeated-measures ANOVA to analyze the bilinguals’ productions across both languages. Findings/conclusions: A significant three-way interaction between Language, Word Status, and Task Type was found for the bilinguals, indicating that the phonetic cognate effect is modulated by both the language context and task demands. Critically, bilinguals exhibited a significant cognate effect in their English productions (shorter VOTs for cognates), a pattern not found to be statistically significant in the native speaker group. Bilinguals’ English VOTs were also significantly shorter overall than those of the native speakers. Originality: This study is the first to investigate phonetic cognate effects in a language pair with differing orthographies (Japanese-English) while also comparing different production tasks and including a native-speaker baseline. Significance/implications: The results provide robust evidence for the continuous co-activation of a bilingual’s two languages during speech production. The findings are discussed within an exemplar-based model of bilingual phonology, highlighting the intricate interplay of lexical and phonetic factors in shaping bilingual speech.

Although previous research has documented the relationship between voice-onset time (VOT) and the production of foreign accent in English and Spanish, less is known about the role of this cue in perception. VOT refers to the aspiration that occurs between the release of a stop consonant and the beginning of the following segment. In Spanish and English, voiceless stop VOTs differ cross-linguistically in the duration of the aspiration. This study presents a quantitative analysis of VOT as it is associated with the degree of foreign accent perceived by 26 native speakers of Spanish and 160 native English speakers learning Spanish. The results show that both listener groups perceived and used VOT duration differences in their judgments of degree of foreign accent in Spanish, although nonnative listeners’ assessments varied according to their course enrollment. The findings suggest that language learners have a concept of what constitutes native-like Spanish and native-like VOTs in Spanish, information that they draw on in judging foreign accent. These results have implications for language instructors and adult language learners as well.

The influence of gender and environmental setting on voice onset time (VOT) was examined. Participants produced six stop consonants paired with three vowels in a consonant + vowel (CV) context. Recordings were made when participants were seated inside a sound booth (laboratory setting) and outside a sound booth (non-laboratory setting). Results of the analysis for VOT and CV duration indicated that females produced voiceless stops with significantly longer VOT durations than males in both settings. Both gender groups produced CV tokens with significantly longer duration in the laboratory setting; however, females continued to produce CV tokens with longer duration in the non-laboratory setting. Findings suggest that differences in the vocal anatomy between genders may account for some but not all differences in temporal measures of speech production. Sociophonetic factors, such as speaking style, may also contribute to gender differences in speaking behavior.

Phonetic accommodation in speech errors has traditionally been used to identify the processing level at which an error has occurred. Recent studies have challenged the view that noncanonical productions may solely be due to phonetic, not phonological, processing irregularities, as previously assumed. The authors of the present study investigated the relationship between phonological and phonetic planning processes on the basis of voice onset time (VOT) behavior in consonant cluster errors. Acoustic data from 22 German speakers were recorded while eliciting errors on sibilant-stop clusters. Analyses consider VOT duration as well as intensity and spectral properties of the sibilant. Of all incorrect responses, 28% failed to show accommodation. Sibilant intensity and spectral properties differed from correct responses irrespective of whether VOT was accommodated. The data overall do not allow using (a lack of) accommodation as a diagnostic as to the processing level at which an error has occurred. The data support speech production models that allow for an integrated view of phonological and phonetic processing.

Why are Korean tense stops acquired so early?: The role of acoustic properties

Second language (L2) production can be a kind of interlanguage, a relatively stable system bearing the nature of both the native language (L1) and L2. Within such a system sound components of a syllable may bear their own interlanguage characteristics and yet interact with the other component sounds. The present study investigates temporal patterns of L1–L2 interaction at the syllable level. Audio recordings were made of English stop-vowel syllables produced by native speakers of Mandarin who were fluent in English (ChE). Native English productions (AmE) of these syllables and native productions of Mandarin (ChM) stop-vowel syllables were acquired as native norms. Temporal measures included stop closure duration, voice-onset time (VOT), vowel duration, and syllable duration. Results show that the internal timing components of ChE often deviate from AmE, with the closure duration, VOT, and vowel duration being intermediate to AmE and ChM. However, at the syllable level, ChE productions tend to follow the overall patterns of AmE. Temporal deviations were often compensated by temporal compensation of other components in the syllable, maintaining a balanced consonant/vowel distribution. These findings have implications for a broader understanding of L2 productions.

Production and perception of English stops by native Spanish speakers

Perception of voice onset time (VOT) has frequently been used to test auditory temporal processing. However, the first formant frequency (F1) of an adjacent vowel systematically covaries with VOT, presenting a confounding spectral cue. The most problematic confound between VOT and F1 would be for a vowel such as /ɑ/, the most commonly used vowel context for VOT studies in the literature. The present study tested the hypotheses that (1) F1 cues influence perception of VOT when followed by the low vowel /ɑ/ but not when followed by the high vowel /i/, and (2) this confounding spectral cue in /ɑ/ is so salient that it is perceptible for cochlear implant users. Stimuli included a /d/-/t/ VOT continuum coupled with /ɑ/ or /i/, where VOT-F1 covariance was controlled through the ratio of VOT duration to the duration of the vowel that was replaced by aspiration (i.e., cutback ratio). For both listener groups, VOT-F1 covariance affected perception of consonants followed by /ɑ/ but not those followed by /i/. Studies pertaining to auditory temporal processing that have used consonant + /ɑ/ stimuli should be reevaluated because of the likely spectral confound. Future work in this area should use the /i/ context to more effectively isolate temporal cues.

Voice onset time (VOT) is a temporal acoustic parameter that reflects motor speech coordination skills. This study investigated the patterns of age and sex differences across development of voice onset time in a group of 70 English-speaking children, ranging in age from 4.1 to 18.4 years, and 12 young adults. The effect of the number of syllables on VOT patterns was also examined. Speech samples were elicited by producing syllables /pa/ and /pataka/. Results supported previous findings showing that younger children produce longer VOT values with higher levels of variability. Markedly higher VOT values and increased variability were found for boys at ages between 8 and 11 years, confirming sex differences in VOT patterns and patterns of variability. In addition, all participants consistently produced shorter VOT with higher variability for multisyllables than monosyllables, indicating an effect of syllable number. Possible explanations for these findings and clinical implications are discussed.

An investigation was made of the role of voice onset time (VOT) in distinguishing among Korean apical stop consonants. Measurements were made of VOT values for word-initial apical stops in the speech of four native Korean speakers. Words in citation form, in test sentences, in conversations among Korean adults, and in mothers' speech to children were used. Our results are not in accord with other experimenters who found complete separation of the aspirated from the strong and weak categories of Korean stops. VOT values for word-initial apical stops in the speech of all four speakers showed considerable overlap of the weak and aspirated categories. The strong and weak categories were also found to overlap, but the overlap in the weak and aspirated categories was greater. Our data suggest that although VOT is sufficient to distinguish the strong from the aspirated stops, it cannot effectively distinguish either of these from the weak stops. Our findings support Kim (1965), who proposes a feature of “tensity,” independent of VOT, to distinguish weak stops from the strong and aspirated stops of Korean.

The ’’phoneme-boundary effect’’ refers to the observation that discrimination of stop consonants across a boundary between phoneme categories is superior to discrimination of comparable stimulus differences within a phoneme category. The present experiment employed signal detection methodology (a) to distinguish between changes in discriminability and response bias; and (b) to reevaluate the role of phonetic categorization in the phoneme-boundary effect. A SAME–DIFFERENT discrimination task compared discrimination of 10− and 20−msec differences in voice onset time (VOT) in a synthetic stimulus continuum ranging from [ba] to [pa] (VOT’s from −50 to +70 msec). Both a clear increase in discriminability and a marked shift in response bias from SAME to DIFFERENT occurred near the voiced–voiceless boundary. When variations in VOT were isolated from syllable context so that they were not categorized as phonemes, discriminability increased near the voiced–voiceless boundary in a manner comparable to the full-syllable stimuli. These data suggest that the phoneme-boundary effect in VOT discrimination reflects a genuine increase in discriminability near the phoneme boundary. However, in agreement with the recent data of J. D. Miller and his colleagues, these results suggest further that the phoneme-boundary effect for VOT is not due exclusively to phonetic categorization but may instead reflect acoustic and auditory properties which are distinct from phonetic processing. Subject Classification: [43]70.30; [43]65.75; [43]70.35..

In this study, multiple measures of voicing acquisition were used to evaluate the extent to which developmental patterns based on voice onset time (VOT) mean data differed from those based on token-by-token analyses in typically developing 2-year-olds. Multiple repetitions of words containing initial /b p d t/ were elicited from 10 English-speaking children biweekly for 4 months. VOT was measured for each stop. For each child, consonant, and recording session, means and ranges were obtained, as were measures of accuracy, discreteness, and overshoot calculated for session means and for individual tokens. The token-by-token analyses suggested lower accuracy and more category overlap than the session means and revealed an overshoot phase for all children. They also showed examples of both abrupt and gradual changes that were not always evident in the means. Measures of range, accuracy, discreteness, and overshoot all continued to change after statistically significant VOT differences were observed. The findings suggest that some aspects of voicing development may not be evident in analyses that rely on VOT mean data and patterns of statistical significance. Token-by-token measures provide a more complete picture of stages of voicing development than those based solely on mean VOT values.