Early Word Segmentation in Naturalistic Environments: Limited Effects of Speech Register

Abstract

We examined 7.5-month-old infants' ability to segment words from infant-and adultdirected speech (IDS and ADS). In particular, we extended the standard design of most segmentation studies by including a phase where infants were repeatedly exposed to target word recordings at their own home (extended exposure) in addition to a laboratorybased familiarization. This enabled us to examine infants' segmentation of words from speech input in their naturalistic environment, extending current findings to learning outside the laboratory. Results of a modified preferential-listening task show that infants listened longer to isolated tokens of familiarized words from home relative to novel control words regardless of register. However, infants showed no recognition of words exposed to during purely laboratory-based familiarization. This indicates that infants succeed in retaining words in long-term memory following extended exposure and recognizing them later on with considerable flexibility. In addition, infants segmented words from both IDS and ADS, suggesting limited effects of speech register on learning from extended exposure in naturalistic environments. Moreover, there was a significant correlation between segmentation success and infants' attention to ADS, but not to IDS, during the extended exposure phase. This finding speaks to current language acquisition models assuming that infants' individual attention to language stimuli drives successful learning.

The impact of the quality of maternal speech on infants’ segmentation abilities

“…This has serious consequences for early language learning in German infants, suggesting that these infants may be unable to segment words from standard German IDS until at least around 9-months of age or -at the very least -may require more input in order to be able to segment words from fluent speech. This finding is in keeping with previous studies showing that, for instance, infants were only able to demonstrate segmentation of words from fluent speech if they had been previously familiarized with similar sounding words (Altvater-Mackensen & Mani, 2013) or that even older infants at 9 months of age were only able to segment words from fluent speech when they had been familiarized with these words over a 6-week-period at home (Schreiner, Altvater-Mackensen, & Mani, 2016). Taken together, these current findings suggest that German infants may require more exposure to the words to be segmented before they are able to segment words from fluent speech.…”

“…Somewhat worryingly, we find that even using a sensitive electrophysiological measure, we do not find segmentation of standard German IDS. This finding is in keeping with previous studies showing that infants from some language backgrounds may need more cues to speech segmentation at early ages, including the use of an exaggerated register, greater exposure to the words to be learned, or to similar-sounding words (Altvater-Mackensen & Mani, 2013;Floccia et al, 2016, Schreiner, Altvater-Mackensen & Mani, 2016Schreiner & Mani, 2017).…”

“…Whereas Spanish-Catalan infants appear to be able to segment speech by as early as 6-months of age (Bosch, Figueras, Teixido, & Ramon-Casas, 2013, but see also Bortfeld, Morgan, Golinkoff, & Rathbun, 2005), infants of other languages seem to need additional cues in order to successfully segment speech at a similar age to American English infants (Jusczyk & Aslin, 1995). German infants, for instance, show successful segmentation of words from fluent speech only if they have previously been familiarized to similar sounding words (Altvater-Mackensen & Mani, 2013), been provided with extended exposure to these words in stories at home (Schreiner, Altvater-Mackensen, & Mani, 2016), or are exposed to the words in isolation first before hearing these words embedded in sentences (Höhle & Weissenborn, 2003).…”

Why Do Children Learn the Words They Do?

“…In a study that used a robotic model of the human vocal tract to investigate phonetic learning (29), choosing auditory goals (i.e., where particular articulators should be in the mouth) that maximize learning progress, based on the model's prior experience, led to curiosity-driven exploration; this mirrors patterns of phonological development in early childhood. Furthermore, research on word-form learning suggests that such curiosity-driven accounts may interact with pedagogical accounts (30). When speech was presented in a salient infant-directed register (i.e., the kind of which speech adults typically direct to infants), differences in children's attention to speech did not affect learning.…”

Familiar words facilitate segmentation of novel similar sounding words in 7-month-olds

“…Infants as early as 7.5 months of age, if not earlier (Altvater-Mackensen & Mani, 2013;Bortfeld, Morgan, Golinkoff, & Rathbun, 2005) have been shown to segment words from fluent speech streams (Jusczyk & Aslin, 1995) and are able to store these word-form representations in long-term memory such that they are able to recognize them later (Jusczyk & Hohne, 1997;Schreiner, Altvater-Mackensen, & Mani, 2016).…”