Purpose: Talkers adapt their speech according to the demands of their listeners and the communicative context, enhancing the properties of the signal (pitch, intensity) and/or properties of the code (enhancement of phonemic contrasts). This study asked how mothers adapt their child-directed speech (CDS) in ways that might serve the immediate goals…

Purpose: The purpose of the present study was to examine whether there is a listening preference for child-directed speech (CDS) over backward speech in moderate-preterm infants (MPIs). Method: Eighteen MPIs of gestational age of 32.0 weeks (range: 32-34.06 weeks), chronological age of 8.09 months, and maturation age of 6.48 months served as the…

A prominent hypothesis holds that by speaking to infants in infant-directed speech (IDS) as opposed to adult-directed speech (ADS), parents help them learn phonetic categories. Specifically, two characteristics of IDS have been claimed to facilitate learning: "hyperarticulation," which makes the categories more "separable," and…

Purpose: The aim of the study was to investigate the effects of specific acoustic patterns on word learning and segmentation in 8- to 11-year-old children and in college students. Method: Twenty-two children (ages 8;2-11;4 [years;months]) and 36 college students listened to synthesized "utterances" in artificial languages consisting of…

Previous studies have shown that infant-directed speech (IDS) differs from adult-directed speech (ADS) on a variety of dimensions. The aim of the current study was to investigate whether acoustic differences between IDS and ADS in English are modulated by prosodic structure. We compared vowels across the two registers (IDS, ADS) in both stressed…

Child speech is highly variable. The speech apparatus--the vocal tract, tongue, teeth, and vocal folds--develop at different rates for different children, which helps explain some of the variability in children's speech. For example, the ratio of the oral to pharyngeal cavities changes as children age, making it difficult to establish reliable…

Studies of connected speech have repeatedly shown that the contextual predictability of a word is related to its phonetic duration; more predictable words tend to be produced with shorter duration, when other factors are controlled for (Aylett & Turk, 2004, 2006; Bell et al., 2003; Bell, Brenier, Gregory, Girand, & Jurafsky, 2009; Gahl,…

Past research has indicated that English-learning infants begin segmenting words from speech by 7.5 months of age (Jusczyk & Aslin, 1995). More recent work has demonstrated, however, that 7.5-month-olds' segmentation abilities are severely limited. For example, the ability to segment vowel-initial words from speech reportedly does not appear until…

The current investigation examined the development of voice onset time (VOT) in Standard-Greek (SG) and Cypriot-Greek (CG)-speaking children at age levels 2;0-2;5, 2;6-2;11, 3;0-3;5, and 3;6-4;0 years. SG presents with a two-way voicing contrast (voiced and voiceless unaspirated stops) whereas CG is a three-way contrast dialect containing…

Purpose: This study examined whether experienced speech-language pathologists (SLPs) differ from inexperienced people in their perception of phonetic detail in children's speech. Method: Twenty-one experienced SLPs and 21 inexperienced listeners participated in a series of tasks in which they used a visual-analog scale (VAS) to rate children's…

In order to examine whether children adjust their phonetic speech categories, children of two age groups, five-year-olds and eight-year-olds, were exposed to a video of a face saying /aba/ or /ada/ accompanied by an auditory ambiguous speech sound halfway between /b/ and /d/. The effect of exposure to these audiovisual stimuli was measured on…

Sound-meaning correspondences produced by an infant were studied under conditions of early rampant homonymy (i.e., production by a very young child of a small set of noncontrastive surface forms or phonetic sequences to refer to objects/events that on the basis of adult standards require the production of numerous contrasting surface forms). The…

Describes and examines three tests using an infant speech identification (ISI) procedure, in which English language environment infants, two- and six-year-old children, and adults were tested for their identification of sounds on a native (voice/voiceless bilabial stop) and a nonnative (prevoiced/voiced bilabial stop) speech continuum. (31…

Behavioral data establish a dramatic change in infants' phonetic perception between 6 and 12 months of age. Foreign-language phonetic discrimination significantly declines with increasing age. Using a longitudinal design, we examined the electrophysiological responses of 7- and 11-month-old American infants to native and non-native consonant…

Early child phonology was studied using phonetically transcribed samples that six parents provided of their children's vocalizations, beginning when the children were about 11 months old and continuing to four years of age. The primary study objective was to obtain a sufficient amount of longitudinal data from several children to support a…