How do monolingual and bilingual infants segment words from continuous speech?

In this study, we investigate whether monolingual English, monolingual Spanish and bilingual English-Spanish infants can find words in Spanish and English. We found that even monolingual English 8-month-olds succeed at finding Spanish words like SALsa that start with a stressed syllable. This replicates results from English-acquiring infants segmenting English words (they succeed with DOCtor). However, in Spanish, they do so when we familiarize them with Spanish stories for 60s (not the typical 45s). Additionally, we have found they also succeed at segmenting words like coRRAL, that end in a stressed syllable given 60s of familiarization time as well. Contrastively, they fail to segment similar words in French. We believe this is due to the fact that French does not have variable stress (it’s always final) while both English and Spanish have lexical stress (PREsent and present have different meanings). English-acquiring infants can therefore segment words from fluent speech by aligning stress to word onsets of offsets so long as the language has lexical stress.

We have also found that bilingual 8mo-olds exposed to both English (>50%) and Spanish (<50%) successfully segment English iambs (guiTAR) and with only 45s of familiarization. This is striking because monolingual English-learning infants fail at segmenting English stress-final words with 45s of familiarization time. We believe bilinguals learn from Spanish to segment words that end with a stressed syllable (40% of Spanish disyllabic words have final stress), and then transfer that knowledge to English, a language in which stress falls 90% on the first syllable. We are currently still testing bilingual English-Spanish infants as well as monolingual Spanish infants.