Local temporal regularities in child-directed speech in Spanish

Abstract

Human neurocognitive mechanisms track the acoustic temporal landmarks of the speech signal to enable comprehension. It is also well-known that adults adapt their speech when addressing children to facilitate comprehension. However, the temporal statistics of child-directed speech (CDS) have not been directly contrasted with those of adult-directed speech (ADS) to specify to what extent they can be exploited by the emergent phonological systems of children. In the present study, we analyzed the temporal regularities of spontaneous and read speech productions of 18 Spanish-speaking women addressing adults (ADS) and children (CDS). We focused on three related metrics of the temporal organization of speech: prosodic and syllabic salience (through the modulation spectrum), regularity of stressed syllables (in terms of delta-theta amplitude modulation phase synchronization), and syllable rate (syllables per second). We found that, while CDS and ADS overlap to a big extent in their modulation spectra and both show syllabic salience, CDS is characterized by a higher regularity of stressed syllables and a slower syllable rate than ADS. These temporal regularities of CDS make it highly supportive to the phonological development of children. Together with previous IDS and ADS findings, our CDS results help to delineate developmental changes in the temporal acoustic speech statistics that human neurocognitive systems need to map for efficient language comprehension across the lifespan.

Hierarchical amplitude modulation structures and rhythm patterns: Comparing Western musical genres, song, and nature sounds to Babytalk

“…Related experimental work using PAD showed that the phase relations between peaks and troughs in AM bands centred on ~2 Hz and ~5 Hz was critical for perceiving rhythmic metrical patterning in nursery rhymes (trochaic versus iambic, [14,15,18,19]). These phase relations between peaks and troughs in AM bands centred on ~2 Hz and ~5 Hz have also been revealed by statistical modelling of other languages like Portuguese and Spanish [20,21]. For example, Pe ´rez-Navarro et al [21] reported that CDS in Spanish was characterized by higher temporal regularity of the placement of stressed syllables (phase synchronization of ~2 Hz and ~5 Hz AM bands) compared to ADS in Spanish.…”

“…These phase relations between peaks and troughs in AM bands centred on ~2 Hz and ~5 Hz have also been revealed by statistical modelling of other languages like Portuguese and Spanish [20,21]. For example, Pe ´rez-Navarro et al [21] reported that CDS in Spanish was characterized by higher temporal regularity of the placement of stressed syllables (phase synchronization of ~2 Hz and ~5 Hz AM bands) compared to ADS in Spanish. Further, phase relations are statistical characteristics that describe music as well as language, and phase relations appear relatively uniform regarding music from different cultures [22,23], as well as songs of different species [24].…”