CVC Target Research Articles

Syllable organization in children’s early American English: Acoustic evidence.

Children’s early CVC target words are often produced with epenthesis or heavily aspirated release (e.g., cat [kæth]). This has led some to suggest that these are actually produced as two-syllables (CV.C(V)) [Goad and Brannen (2003)]. To evaluate this claim, this study conducted an acoustic investigation of syllable timing in American English 2-year-olds’ production of CVC words. These were compared with productions of disyllabic CV.CV words. For adults, V1 duration and C2-closure duration were expected to be longer in CVC than in CV.CV words [Lehiste (1972); Lisker (1972)]. However, if durations were found to be similar across conditions for children, this might support the claim that children syllabify CVC words as two syllables (CV.C(V)). Participants were three 2-year-olds (mean=2;4) and three adults (mean=23). The stimuli were 4 prerecorded nonce words (/bɑk/, /bɑg/, /bɑkə/, /bɑgə/). Speech productions were sampled at 44 kHz and four repetitions of each word were acoustically analyzed. As predicted, adults showed significantly longer V1 and C2-closure durations in CVC compared to the CV.CV targets (p <0.01). Children showed more variable, non-significant trends (p =0.06). This suggests that 2-year-olds are not treating CVC forms like disyllables, nor are they adult-like in their timing relations. [Work supported by NIH R01HD057606.]

Perceived imitation of regional dialects.

This study examined the effect of regional dialect on perceived spontaneous phonetic imitation. Participants shadowed CVC target words produced by talkers from two American English dialect regions, the North and the Midland. Imitation was measured acoustically in terms of vowel quality, vowel duration, midpoint f0, f0 trajectory, and onset and coda consonant duration. The productions and targets from the shadowing task were then used as stimulus materials in an AXB discrimination task to measure perceived imitation. Listeners selected whether the shadowed production of each word was more similar to the target (X) than a baseline recording of that same word. The AXB experiment included three conditions to distinguish between imitation of talker-specific and dialect-specific properties, in which X was the original target from the shadowing experiment, X was produced by another talker from the same region, or X was produced by a talker from the other region, respectively. Preliminary results suggest that listeners used talker-specific, rather than dialect-specific, properties when judging imitation. Among the acoustic measures, perceived imitation was correlated with vowel duration. These results suggest that talkers in a shadowing task imitate talker-specific variability more than general properties of regional dialect.

The Role of Phonotactic Frequency in Sentence Repetition by Children With Specific Language Impairment

Recent work suggests that specific language impairment (SLI) results from a primary deficit in phonological processing. This deficit is most striking in nonword repetition tasks, where semantic and syntactic demands are eliminated. Children with SLI repeat nonwords less accurately than do their unimpaired peers, which may reflect difficulty extracting phonological regularities from their lexicons. However, recent evidence suggests that having children with SLI respond to meaningless syllables such as nonwords underestimates their language abilities. Therefore, phonological processing was measured by having children repeat meaningful sentences containing target words differing in phonotactic pattern frequency (PPF). Eighteen children with SLI (mean age=9;0 [years;months]) and 18 age-matched controls repeated acoustically degraded sentences containing CVC target words differing in PPF, occurring in either subject position or sentence-final position. Accuracy results revealed significant main effects due to group, PPF, and sentence position (sentence final>subject). Further, the nonsignificant Group×PPF interaction suggests that both groups of children were similarly affected by PPF. Children with SLI repeated CVC target words less accurately overall but showed similar sensitivity to PPF as typical controls, suggesting that PPF affects repetition of real words embedded in sentential contexts by both children with SLI and typically developing peers.

Speech production in experienced cochlear implant users undergoing short-term auditory deprivation

This study examined the effect of short-term auditory deprivation on the speech production of five postlingually deafened women, all of whom were experienced cochlear implant users. Each cochlear implant user, as well as age and gender matched control speakers, produced CVC target words embedded in a reading passage. Speech samples for the deafened adults were collected on two separate occasions. First, the speakers were recorded after wearing their speech processor consistently for at least two to three hours prior to recording (implant ‘‘ON’’). The second recording occurred when the speakers had their speech processors turned off for approximately ten to twelve hours prior to recording (implant ‘‘OFF’’). Acoustic measures, including fundamental frequency (F0), the first (F1) and second (F2) formants of the vowels, vowel space area, vowel duration, spectral moments of the consonants, as well as utterance duration and sound pressure level (SPL) across the entire utterance were analyzed in both speaking conditions. For each implant speaker, acoustic measures will be compared across implant ‘‘ON’’ and implant ‘‘OFF’’ speaking conditions, and will also be compared to data obtained from normal hearing speakers.

Effects of speaking rate on temporal patterns of English

Previous research [B. L. Smith, J. Acoust. Soc. Am. 108, 2438–2442 (2000)] has indicated that individual subjects show considerable variation in the extent to which they manifest a number of temporal patterns in their speech (e.g., vowel lengthening before voiced obstruents, final-syllable vowel lengthening, etc.). At least in part, some of the variation across speakers was found to be related to the fact that some subjects naturally tend to talk somewhat faster/slower than others. The present study extended these previous findings concerning variations in temporal performance related to rate of speech by having 15 subjects produce several different CVC target stimuli in sentences spoken at both normal and fast rates. The temporal patterns observed as a function of these experimental manipulations of speaking rate generally supported the previous findings related to natural variations in rate of speech across subjects. It was found, for example, that vowel lengthening preceding voiced obstruents tended to be less when subjects spoke at a fast versus a normal rate. In contrast, phrase-final vowel lengthening was typically greater when subjects spoke at a faster rate. Possible reasons for these different vowel-lengthening effects may relate to the temporal domain that influences them.

Sequence detection in pseudowords in French: Where is the syllable effect?

In two experiments, French speakers detected cv or cvc sequences at the beginning of disyllabic pseudowords varying in syllable structure and pivotal consonant. Overall, both studies failed to replicate the crossover interaction that has been previously observed in French by Mehler, Dommergues, Frauenfelder and Seguí (1981). In both experiments, latencies were shorter to cv than to cvc targets and this effect of target length was generally smaller for cvc cv than for cv cv carriers. However, a clear crossover interaction was observed for liquid pivotal consonants under target-blocking conditions, and especially for slow participants. A third experiment collected phonemegating data on the same pseudowords to obtain estimates of the duration of the initial phonemes. Regression analyses showed that phoneme duration accounted for a large proportion of the variance for cvc target detection, suggesting that participants were reacting rather directly to phonemic throughput. These findings argue against the hypothesis of an early syllabic classification mechanism in the perception of speech.

The status of the syllable in the perception of spanish and englisb

Abstract A series of monitoring studies is reported, in replication of the cross-language research of Cutler, Mehler, Norris and Segui (1983; 1986), which found evidence of language-specific perceptual routines. Monolingual speakers of Spanish and English detected CV and CVC target sequences in native and non-native materials. The replication succeeded only in the case of Spanish speakers and Spanish materials, where a cross-over interaction of target (CV vs CVC sequences) and carrier types (CV- vs CVC-syllabitied words) gave evidence of a sensitivity to the input's syllabification; no such pattern emerged for Spanish speakers and English materials, nor for English speakers and materials in either language. For English speakers, the consistent finding was for faster performance with CVC targets, regardless of the structure of the carrier word. Whether or not this is to be interpreted as evidence of syllabified input representations is not clear. Analyses of English syllabification that arc alternatives to...

A cinefluorographic investigation of repeated fluent productions of stutterers in an adaptation procedure.

Cinefluorography was used to study three stutterers and two nonstutterers repeating a passage made up of monosyllables. CVC target words of the form/caet/ were embedded in the passage and were analyzed to determine the effects of repeating the passage on velocities, displacements, and durations of movements of the tongue, jaw, and lower lip. Coordination among the articulators was also assessed. The investigation was undertaken to test the hypothesis that decreases in velocities and displacements, increased movement durations, and decreased latency between the onsets of jaw movements and of tongue tip movements would be associated with the repeated readings. The hypothesis was not supported by the results. A post hoc analysis showed that a decrease in the variability of instantaneous velocities (and by inference a decrease in variation in muscle stiffness) was associated with practice for the three stutterers but not for the nonstutterers. Inferences about the adaptation effect are made related (a) to the stabilization of tonic muscle activity which may be associated with a decrease in arousal, and (b) to the effects of practice.

Some context effects on voice onset time

Systematic variance in measures of voice onset time (VOT) has been attributed primarily to place of articulation and position of stress relative to the target segment. Although data are available regarding other influences (e.g., rate) on VOT, we are unaware of any information regarding effects of phonetic contexts on this measure of glottal-supraglottal timing. As a result of post hoc we observations from a previous study [Klee, Weismer, and Ingrisano, J. Acoust. Soc. Am. 60, S63(A) (1976)] concerning context effects on VOT, an experiment was designed in which fluctuations in VOT of the first consonant in CVC target words could be observed as we systematically varied the tense/lax and voicing features of the interconsonantal vowel and final consonant, respectively. Our results indicate that, for the initial consonant in a CVC target word, (1) longer VOT's are associated with tense, as compared with lax, interconsonantal vowels, (2) longer VOT's are associated with voiced, as compared with voiceless, final consonants, and, (3) the interactive effect of interconsonantal vowel and final consonant features on VOT appears to be extremely complex.