Electronic Theses and Dissertations


Janine Peca



Document Type


Degree Name

Master of Arts


Communication Sciences & Disorders

Committee Chair

Kimbrough Oller

Committee Member

Naomi Eichorn

Committee Member

Justine Springs


A female language advantage has been widely reported, although it has not been consistently shown across the literature. Perhaps surprisingly, the possibility of sex differences in prelinguistic vocalizations in the first year has not been widely studied. A paper published in Current Biology in 2020 found that infant males produced a significantly larger number of speech-like vocalizations through 12 months of age than infant females based on human coding of randomly-selected samples from all-day recordings. The authors argued that their sampling method offered a maximally representative view of infant vocalization. The present study also investigated possible sex differences in the first year, but the sample was much smaller than the prior one, and the data were collected in the much more limited circumstance of brief laboratory recordings where parents were instructed to interact with infants. Thus the new study offered the opportunity to shed new light on possible sex differences in early vocalization because the new study addressed a very different circumstance (parent-elicited vocalization in a brief laboratory recording) than the Current Biology study (naturally occurring vocalization in the home, all day long). Also the new study included data through 18 months, a point where infants are expected to be talking and where consequently we might imagine a female advantage in well-formed speech-like utterances to be discernible. We hypothesized that the laboratory recordings might inspire girls to be more vocal than they would be all-day at home, nullifying any possible difference in amount of vocalization across the sexes as seen in the Current Biology paper. Further we considered the possibility that an advantage for girls might appear in the period from 12 to 18 months in the form of more speech-like utterances from girls than boys. The findings indicated no clear sex advantage in amount of vocalization in the first 18 months of life, but provided tentative evidence of a female advantage in speech-like utterances in the period from 12 to 18 months.


Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest.


Open access