Characteristics Of Infant-directed Speech Research Articles

Characteristics of infant-directed speech in caregivers with traumatic experiences

Mothers with depressive symptoms interact differently with their children compared to mothers without depressive symptoms. Compared with non-depressed mothers, depressed mothers use a lower mean pitch and less extended pitch range, speak less, and respond slower to their infants. Are the characteristics of infant-directed speech (IDS) affected by a caregiver’s traumatic experiences? The study will examine characteristics of IDS in two groups of mothers (N=30); one group exposed to traumatic experiences and the other not exposed to traumatic experiences as assessed by the Adverse Childhood Experiences scale. The mean length of utterances (MLU, the number of morphemes per utterance), mean fundamental frequency (Hz), fundamental frequency range (Hz), speech rate (syllabus per utterance duration), and utterance duration (seconds) will be measured in maternal speech. Based on studies with depressed mothers, it is expected that mothers exposed to traumatic experiences will produce shorter MLU, lower fundamental frequency, less expanded fundamental frequency range, slower speech rate, and shorter utterance duration compared to mothers without traumatic experiences. The research will contribute to the development of early intervention strategies that will aim to strengthen language acquisition in children from families exposed to trauma.

Infant-Directed Speech From a Multidimensional Perspective: The Interplay of Infant Birth Status, Maternal Parenting Stress, and Dyadic Co-regulation on Infant-Directed Speech Linguistic and Pragmatic Features.

Infant-directed speech (IDS), the particular form of spontaneous language observed in interactions between parents and their infants, is a crucial aspect of the mother-infant interaction and an index of the attunement of maternal linguistic input to her infant communicative abilities and needs during dyadic interactions. The present study aimed to explore linguistic and pragmatic features of IDS during mother-infant interactions at 3-month of infant age. The effects of infant (birth status: preterm vs. full-term birth), maternal (perceived parenting stress) and dyadic (dyadic co-regulation) factors on IDS were explored. Results evidenced few differences between the groups on IDS linguistic characteristics. Moreover, observing the interaction of birth status and dyadic co-regulation, full-term mothers varied their IDS pragmatic features according to the quality of co-regulation while preterm mothers did not. Parenting stress was associated to specific linguistic IDS features independently from the birth status. Findings are discussed underling implications for the study of preterm dyads interactions and the importance to consider the interplay of several factors in affecting the quality of IDS.

The impact of child age and sentence-type on the acoustics of infant-directed speech

Research has demonstrated differences in the characteristics of infant-directed speech (IDS) based on age (Stern et al., 1983) and sentence-type (Geffen and Mintz, 2017) but has not examined the two factors together. The current study evaluates whether the acoustics of IDS differ as a function of child's age and sentence-type. The study combines two corpora of native-English adult speakers. Both Corpus1(9mo) (described in Geffen and Mintz, 2017), from the Brent corpus of the CHILDES database (Brent and Siskind, 2001) and Corpus2 (12mo) (described in Thompson, 2019), from naturalistic home-recordings, included statements, yes/no and wh-questions, and were acoustically coded in Praat. Three 2-way mixed ANOVAs with Age (9 and 12 months; between-subjects factor) and Sentence-Type (S, WH, YN; within-subjects factor) on OverallF0range, FinalVowelDuration, and FinalVowelF0range found main effects of Age, and Age X Sentence-Type interaction for OverallF0range. There was also a significant effect of Age on FinalVowelDuration. Results demonstrated a developmental shift in acoustic characteristics of IDS, with more exaggerated prosody to younger infants, supporting Stern et al. (1983) and suggests that IDS to older children no longer privileges prosody as strongly. Future studies should investigate whether similar developmental adjustments in IDS occur in languages other than English.

Effects of Gender, Parental Role, and Time on Infant- and Adult-Directed Read and Spontaneous Speech.

Purpose The study sets out to investigate inter- and intraspeaker variation in German infant-directed speech (IDS) and considers the potential impact that the factors gender, parental involvement, and speech material (read vs. spontaneous speech) may have. In addition, we analyze data from 3 time points prior to and after the birth of the child to examine potential changes in the features of IDS and, particularly also, of adult-directed speech (ADS). Here, the gender identity of a speaker is considered as an additional factor. Method IDS and ADS data from 34 participants (15 mothers, 19 fathers) is gathered by means of a reading and a picture description task. For IDS, 2 recordings were made when the baby was approximately 6 and 9 months old, respectively. For ADS, an additional recording was made before the baby was born. Phonetic analyses comprise mean fundamental frequency (f0), variation in f0, the 1st 2 formants measured in /i: ɛ a u:/, and the vowel space size. Moreover, social and behavioral data were gathered regarding parental involvement and gender identity. Results German IDS is characterized by an increase in mean f0, a larger variation in f0, vowel- and formant-specific differences, and a larger acoustic vowel space. No effect of gender or parental involvement was found. Also, the phonetic features of IDS were found in both spontaneous and read speech. Regarding ADS, changes in vowel space size in some of the fathers and in mean f0 in mothers were found. Conclusion Phonetic features of German IDS are robust with respect to the factors gender, parental involvement, speech material (read vs. spontaneous speech), and time. Some phonetic features of ADS changed within the child's first year depending on gender and parental involvement/gender identity. Thus, further research on IDS needs to address also potential changes in ADS.

How Do Infants Disaggregate Referential and Affective Pitch?

Infants are faced with a challenge of disaggregating functions of pitch in the ambient language into affective, pragmatic or referential (the latter in tone languages only). This mini review discusses several factors that might facilitate the disaggregation of referential and affective pitch in infancy: acoustic characteristics of infant-directed speech, recognition of vocal affect, facial cues accompanying affective prosody, and lateralization of affective and referential prosody in the brain. It proposes two hypotheses concerning the role of audiovisual cues and brain lateralization

Infant-directed speech is consistent with teaching.

Infant-directed speech (IDS) has distinctive properties that differ from adult-directed speech (ADS). Why it has these properties-and whether they are intended to facilitate language learning-is a matter of contention. We argue that much of this disagreement stems from lack of a formal, guiding theory of how phonetic categories should best be taught to infantlike learners. In the absence of such a theory, researchers have relied on intuitions about learning to guide the argument. We use a formal theory of teaching, validated through experiments in other domains, as the basis for a detailed analysis of whether IDS is well designed for teaching phonetic categories. Using the theory, we generate ideal data for teaching phonetic categories in English. We qualitatively compare the simulated teaching data with human IDS, finding that the teaching data exhibit many features of IDS, including some that have been taken as evidence IDS is not for teaching. The simulated data reveal potential pitfalls for experimentalists exploring the role of IDS in language learning. Focusing on different formants and phoneme sets leads to different conclusions, and the benefit of the teaching data to learners is not apparent until a sufficient number of examples have been provided. Finally, we investigate transfer of IDS to learning ADS. The teaching data improve classification of ADS data but only for the learner they were generated to teach, not universally across all classes of learners. This research offers a theoretically grounded framework that empowers experimentalists to systematically evaluate whether IDS is for teaching. (PsycINFO Database Record

Infant-directed speech to infants with a simulated hearing loss.

The acoustic/phonetic features of infant-directed speech (IDS) were measured during face-to-face interactions between mothers and their six-month-old normal hearing infants (N=32) using a setup in which the mother and infant are seated in separate rooms and interact over their respective video monitors. There were two sound conditions, (i) a hearing condition in which infants could hear their mothers at 55 dB SPL, and (ii) a hearing loss condition in which the sound was turned off, and the infants could not hear their mothers. All mothers were told your baby cannot hear you. Mothers and infants interacted for 10 min using three labeled toys (sheep, shoe, and shark) to facilitate the production of exemplars of the corner vowels /i/, /u/, and /a/. The results showed that mean fundamental frequency (F0), F0 range, and the duration of the IDS vowels were comparable across the two conditions. However, vowel hyperarticulation was only evident in the hearing condition, not in the hearing loss condition. These results suggest that mothers adapt their speech input according to signs of infant responsiveness. That is, when their infant cannot hear them, they maintain their modifications to IDS F0 and duration, but at the expense of vowel hyperarticulation.

Articulatory exaggerations during infant directed speech

Although a growing body of literature suggests a principal role for observational learning in the acquisition of speech, the facial movements of infant directed speech (IDS) have rarely been studied. Identifying both the auditory and visual features of IDS is an essential step toward understanding the contribution of environmental stimulation to the development of speech and language. The current project uses three-dimensional motion capture technology to describe how parents modify their articulatory movements when communicating with their infants. The following three experimental questions will be addressed: (1) Do parents exaggerate articulatory gestures during IDS?; (2) If so, are there individual differences among parents in the degree of IDS?; and (3) Is there a strong association between acoustic and movement characteristics of IDS? Mouth movements were recorded from twenty-four mothers while speaking to their infants and to an unfamiliar adult. Mouth shapes during four target vowels were measured for differences in maximum vertical separation, maximum horizontal spread, and duration across speaking conditions. The result indicated that the majority of mothers exaggerated their lip movements when speaking to their infants. Speculation is made regarding the potential role of articulatory exaggerations in early speech learning.

Prosodic differences in mothers' speech to toddlers in quiet and noisy environments

We examined mothers' speech to 2-year-old children in both quiet and moderately noisy conditions. Mothers were recorded while teaching their children two words, one of which occurred in the context of other people speaking. Parents used characteristics of infant-directed speech (IDS) to these older children. Even more interesting was that many of the prosodic changes typical in IDS were accentuated in noise. In a context in which multiple people were speaking simultaneously, mothers spoke to their children with both increased pitch and increased word duration relative to when they spoke in a quiet condition. However, these changes were quite small, lending only mixed support to proposals that one of the advantages of IDS is that it is easier to separate from background noise.