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Comprehending spoken words requires a lexicon of sound patterns and knowledge of their referents in the world. Tincoff and Jusczyk (1999) demonstrated that 6-month-olds link the sound patterns 'Mommy' and 'Daddy' to video images of their parents, but not to other adults. This finding suggests that comprehension emerges at this young age and might take the form of very specific word-world links, as in 'Mommy' referring only to the infant's mother and 'Daddy' referring only to the infant's father. The current study was designed to investigate if 6-month-olds also show evidence of comprehending words that can refer to categories of objects. The results show that 6-month-olds link the sound patterns 'hand' and 'feet' to videos of an adult's hand and feet. This finding suggests that very early comprehension has a capacity beyond specific, one-to-one, associations. Future research will need to consider how developing categorization abilities, social experiences, and parent word use influence the beginnings of word comprehension. [ABSTRACT FROM AUTHOR]

Infants' long-term memory for the phonological patterns of words versus the indexical properties of talkers' voices was examined in 3 experiments using the Headturn Preference Procedure (D. G. Kemler Nelson et al., 1995). Infants were familiarized with repetitions of 2 words and tested on the next day for their orientation times to 4 passages-2 of which included the familiarized words. At 7.5 months of age, infants oriented longer to passages containing familiarized words when these were produced by the original talker. At 7.5 and 10.5 months of age, infants did not recognize words in passages produced by a novel female talker, In contrast, 7.5-month-olds demonstrated word recognition in both talker conditions when presented with passages produced by both the original and the novel talker. The findings suggest that talker-specific information can prime infants' memory for words and facilitate word recognition across talkers. [ABSTRACT FROM AUTHOR]

The Possible Word Constraint limits the number of lexical candidates considered in speech recognition by stipulating that input should be parsed into a string of lexically viable chunks. For instance, an isolated single consonant is not a feasible word candidate. Any segmentation containing such a chunk is disfavored. Five experiments using the head-turn preference procedure investigated whether, like adults, 12-month-olds observe this constraint in word recognition. In Experiments 1 and 2, infants were familiarized with target words (e.g., rush), then tested on lists of nonsense items containing these words in “possible” (e.g., “niprush” [nip + rush]) or “impossible” positions (e.g., “prush” [p + rush]). The infants listened significantly longer to targets in “possible” versus “impossible” contexts when targets occurred at the end of nonsense items (rush in “prush”), but not when they occurred at the beginning (tan in “tance”). In Experiments 3 and 4, 12-month-olds were similarly familiarized with target words, but test items were real words in sentential contexts (win in “wind” versus “window”). The infants listened significantly longer to words in the “possible” condition regardless of target location. Experiment 5 with targets at the beginning of isolated real words (e.g., win in “wind”) replicated Experiment 2 in showing no evidence of viability effects in beginning position. Taken together, the findings suggest that, in situations in which 12-month-olds are required to rely on their word segmentation abilities, they give evidence of observing lexical viability constraints in the way that they parse fluent speech. [Copyright &y& Elsevier]

Examines developments in acquiring native language sound organization during infancy. Capacities for discriminating and categorizing speech sounds; Sensitivity to native language; Impact of the changes in speaking rates on the acoustic characteristics of speech sounds.

As infants learn the sound organization of their native language, they use this developing knowledge to make their first attempts to extract the underlying structure of utterances. Although these first attempts fail to capture the full complexity of features that adults use in perceiving and producing utterances, they provide learners with the opportunity to discover additional cues to the underlying structure of the language. Three examples of this developmental pattern are considered: learning the rhythmic organization of the native language, segmenting words from fluent speech, and identifying the correct units of grammatical organization. [ABSTRACT FROM AUTHOR]

According to the nativist interpretation of Optimality Theory (Prince and Smolensky (1993)), all language learners are born with a set of universal constraints. Learnability arguments entail that, in the initial state, markedness constraints outrank faithfulness constraints (Prince (personal communication, September 26, 1993), Smolensky (1996a), Tesar and Smolensky (2000)). This study investigates whether English learners give evidence of observing markedness and faithfulness constraints relating to nasal place assimilation. Employing the Headturn Preference Procedure (Jusczyk (1998b), Kemler Nelson et al. (1995)), these investigations introduce a general experimental paradigm for exploring infants' phonological grammars. English learners at 4.5 and 10 months of age gave evidence of observing both markedness and faithfulness constraints and ranked markedness above faithfulness. After a brief instability around 15 months, at 20 months they display the adult English pattern, with markedness outranking faithfulness. [ABSTRACT FROM AUTHOR]

Investigates the sensitivity of infants to recurring sound patterns in fluent speech. Mechanism of word segmentation in infants; Difficulty in segmenting vowel initial verbs and consonant initial words; Influence of phonemic make-up of words on word segmentation in infants.

Examines the word segmentation cue of the eight-months-old infants. Utilization of headturn preference procedure in investigating the integration of multiple cues; Continuous stream of speech based on statistical cues; Preference of subtle speech produced by co-articulation.

Explores the infants' representations of the sound patterns of words. Examination of the effects of talker variability on the recognition of words in fluent speech; Infants' familiarization with isolated words; Role for talker-voice similarity in infants' ability to generalize word tokens; Role of indexical properties relating to the vocal characteristics of particular talker.

Discusses the evolution of infants' language-discrimination abilities. Influence of the rhythm of one's native language on on-line speech processing; Language discrimination abilities of English-learning 5-month-olds babies; Infant's ability to discriminate between rhythmic classes; Infants' reliance on prosodic information to distinguish the native language.

Presents information on a series of experiments which explored English-learning infants' capacities to segment bisyllabic words from fluent speech. Experimental procedures; Results and discussions; Conclusions.

Present information on four experimental studies conducted to examine the issue of speech segmentation in 9-month-old infants. Overview of infants' speech perception and production; Definitions of phonotactics, phonotactic awareness and phonotactic sequences; Methodology; Results and discussions.

Explores nine-month-old English-learners' sensitivity to intrasyllabic constituents. Exposure of the infants to syllabic and non-syllabic structures; Sensitivity of the subjects to shared features that occur at the beginnings, but not at the ends of syllables; Attention to the beginnings of syllables as a consequence of changes taking place in other domains of language acquisition.

Examines the potential role that sensitivity to predominant stress pattern of words play in lexical development. First experiment showing that by nine months of age American infants listen longer to words with strong/weak stress patterns than to words with weak/strong stress patterns; Experiment Two showing no significant preferences in six-month old infants; More.

Learning to speak and understand a language involves acquiring a vocabulary. At a minimum, the learner must be able to recognize and identify a set of sound patterns and attach these to their appropriate meanings. If the sound patterns were presented one at a time, or with clear pauses between adjacent words, then the first step would be a matter of discriminating and remembering the different patterns. However, in everyday speech, talkers rarely pause between words. Adults are rarely aware of this difficulty in their own language because they have learned to use cues to word boundaries that are available in the speech signal. The word segmentation problem typically becomes apparent when one listens to speech in an unfamiliar language.

Discusses whether infants are sensitive to syllable weight, a linguistic factor governing the assignment of English lexical stress. Research showing that nine-month-old infants listened longer to words exhibiting Strong-Weak rather than Weak-Strong stress pattern; Evidence that infants prefer both words that begin with a Strong syllable and Strong syllables that are heavy; Suggestion that sensitivity to surface linguistic patterns and the principles that underlie them may be independent in early language acquisition.

Examines the issue of how speech sounds may be treated by infants as special signals relative to other kinds of acoustic stimuli. Consideration of the mechanisms underlying the infant's perception of speech; Processing of speech in the inherent salience which such sounds have for infants; Development of speech perception following the course of a guided learning process.

Studies the capacities of 7 1/2 infants to detect repeated words in fluent English speech. Importance of the acquisition of a vocabulary of words in the native language; Capability of infants to detect words in sentential contexts; Sensitivity of infants to other regularities in native language sound input.

Ponders how young learners might parse speech into linguistically relevant units. Possible sensitivity to prosodic markers of these segments; Seven experiments which examined infants' sensitivity to acoustic correlates of phrasal units in English; Language acquisition; Paucity of studies on how a child arrives at the correct segmentation of speech; More.

Examines 2- to 3-month-olds' representations of bisyllables by familiarizing them with sets of bisyllables that either did or did not share a common consonant-vowel (CV) syllable. Structure of infant's representation of speech sound; Syllables as important units in infant's representation of speech; Role of sensitivity to acoustic structure of input in acquisition of language.

Determines infant's recognition of the sound patterns of their own names. Indications of research on early cognitive and perceptual capacities; Demonstration of sensitivity by young infants; Precocious capacities of infants.

Studies infants' sensitivity to phrase structure in music using a visual preference procedure. Division of Mozart minuets into segments; Significance of the infants' behavior; Correlations between certain musical variables and the infants' preferences for the musical passages.

Reports on the exploration into the long-term retention patterns of words in infants. Use of recorded children's stories; Exposure of the 8 months old infants to these stories; How infants listened to lists of words from the stories after two weeks; Other findings.

In 4 studies, 7.5-month-olds used synchronized visual–auditory correlations to separate a target speech stream when a distractor passage was presented at equal loudness. Infants succeeded in a segmentation task (using the head-turn preference procedure with video familiarization) when a video of the talker's face was synchronized with the target passage (Experiment 1, N=30). Infants did not succeed in this task when an unsynchronized (Experiment 2, N=30) or static (Experiment 3, N=30) face was presented during familiarization. Infants also succeeded when viewing a synchronized oscilloscope pattern (Experiment 4, N=26), suggesting that their ability to use visual information is related to domain-general sensitivities to any synchronized auditory–visual correspondence. [ABSTRACT FROM AUTHOR]

Abstract: Infants were familiarized with fluent speech containing target word sequences coincident with or straddling clauses. Infants later preferred new passages containing the target sequences heard as clause-coincident during familiarization and test, suggesting that prosodic cohesiveness influences infants’ encoding and recognition of speech. [Copyright &y& Elsevier]

Recent investigations with English-learning infants have shown that the rhythmic properties of English influence how infants segment fluent speech. In particular, 7.5-month-old infants have been shown to extract bisyllabic words that conform to the predominant strong/weak stress pattern of English but not weak/strong words. The present series of studies examined whether English-learning 7.5-month-olds' segmentation abilities are limited to extracting strong/weak bisyllables or whether they are able to segment longer strings, such as trisyllables (strong/weak/strong). The results indicated that infants can segment trisyllabic words from fluent speech but only when the first syllable receives primary stress (e.g., cantaloupe ). When primary stress falls on the last syllable (e.g., cavalier ), infants segment only the final stressed syllables. Overall, the findings suggest that 7.5-month-old English-learning infants are able to segment longer strings, and that they use stress as a major cue in segmentation. English-learners appear to equate strong syllables with word onsets only when the strong syllable receives primary stress. [ABSTRACT FROM AUTHOR]

In this study, we used the splitscreen preferential looking paradigm to test 13-, 15-, and 20-month-olds' developing understanding of simple matrix what-questions of the forms "What hit the X?" (subject-question) and "What did the X hit?" (object-question). Infants responded appropriately to subject-questions by 15 months of age, and to both subject- and object-questions by 20 months. At no age did infants look longer toward the object overtly mentioned in the question, as might be expected based on a surface account of early language acquisition. This suggests that infants may have some understanding of these complex structures long before they are produced. [ABSTRACT FROM AUTHOR]

Investigates the role of prosodic structure for the recognition of embedded word sequences in infancy. Segmentation of the input for preserving the important units determined by the grammar; Use of cues available in speech signal for input segmentation; Role of infants' sensitivity to prosodic cues on processing and organizing natural speech.

Two studies examined relationships between infants' early speech processing performance and later language and cognitive outcomes. Study 1 found that performance on speech segmentation tasks before 12 months of age related to expressive vocabulary at 24 months. However, performance on other tasks was not related to 2-year vocabulary. Study 2 assessed linguistic and cognitive skills at 4-6 years of age for children who had participated in segmentation studies as infants. Children who had been able to segment words from fluent speech scored higher on language measures, but not general IQ, as preschoolers. Results suggest that speech segmentation ability is an important prerequisite for successful language development, and they offer potential for developing measures to detect language impairment at an earlier age. [ABSTRACT FROM AUTHOR]

Two experiments sought to extend the demonstration of English-learning infants' abilities to segment nouns from fluent speech to a new lexical class: verbs. More over, we explored whether two factors previously shown to influence noun segmentation, stress pattern (strong-weak or weak-strong) and type of initial phoneme (consonant or vowel), also influence verb segmentation. Our results establish the early emergence of verb segmentation in English: by 13.5 months for strong-weak consonant- or vowel-initial verbs and for weak-strong consonant-initial verbs; and by 16.5 months for weak-strong verbs beginning with a vowel. This generalizes previous reports of early segmentation to a new lexical class, thereby providing additional evidence that segmentation is likely to contribute to lexical acquisition. The effects of stress pattern and onset type found are similar to those previously obtained for nouns, in that verbs with a weak-strong stress pattern and verbs beginning with a vowel appear to be at a disadvantage in segmentation. Finally, we present prosodic analyses that suggest a possible effect of prosodic boundary and pitch accent distribution on segmentation. These prosodic differences potentially explain a developmental lag in verb segmentation observed in the present study compared to earlier findings for noun segmentation. [ABSTRACT FROM AUTHOR]

The current study explores infants’ use of prosodic cues coincident with phrases in processing fluent speech. After familiarization with two versions of the same word sequence, both 6- and 9-month-olds showed a preference for a passage containing the sequence as a noun phrase over a passage with the same sequence as a syntactic non-unit. However, this result was found only in one of the two groups, the group exposed to a stronger prosodic difference between the syntactic and non-syntactic sequences. Six month olds were tested in the same way on passages containing verb phrases. In this case, both groups preferred the passage with the verb phrase to the passage with the same word sequence as a syntactic non-unit. These results provide the first evidence that infants as young as 6 months old are sensitive to prosodic markers of syntactic units smaller than the clause, and, in addition, that they use this sensitivity to recognize phrasal units, both noun and verb phrases, in fluent speech. This ability to use phrase-level prosodic cues is variable, however, and appears to depend on the strength or number of cues associated with these syntactic units. [Copyright &y& Elsevier]