The Relationship Between Infant-Directed Prosody and Indices of Lexical Acquisition at 15 Months of Age
Date
2002
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Producer
Director
Performer
Choreographer
Costume Designer
Music
Videographer
Lighting Designer
Set Designer
Crew Member
Funder
Rehearsal Director
Concert Coordinator
Advisor
Moderator
Panelist
Alternative Title
Department
Swarthmore College. Dept. of Linguistics
Type
Thesis (B.A.)
Original Format
Running Time
File Format
Place of Publication
Date Span
Copyright Date
Award
Language
en_US
Note
Table of Contents
Terms of Use
Full copyright to this work is retained by the student author. It may only be used for non-commercial, research, and educational purposes. All other uses are restricted.
Rights Holder
Access Restrictions
Terms of Use
Tripod URL
Identifier
Abstract
The prosodic features of infant -directed speech are described, and several accounts of
potential facilitative effects of such distinct prosodic features for the infant's
socioemotional and/or linguistic development are discussed. One of these accounts--that
infant-directed prosody facilitates word learning by exaggerating the perceptual salience
of novel words in the discourse--is then evaluated through an analysis of two pairs of
audio samples taken from the corpora of the Child-Directed Speech Project of the
Language Science Research Group based at Washington University at St. Louis. The
samples selected were recordings of naturalistic interactions between two mothers and
their infants when the infants were nine-and-a-half and 15 months of age. The global
prosodic characteristics of the mothers' speech in both the nine-and-a-half- and 15-month
samples were assessed and compared to the level of productive language demonstrated by
the infants at 15 months, an analysis which yielded no significant effects. In addition,
based on previous reports that mothers highlight new and/or semantically focused words
in speech to infants by placing such words on utterance-final pitch peaks, the pitch peaks
of 40 maternal utterances in each I5-month sample were analyzed to determine how
concentrated they were at the ends of utterances and how often they signaled emphatic
stress of semantically focused information. Pitch peaks were found to coincide with
emphatically stressed words much more often if they occurred utterance-finally than if
they occurred elsewhere. The hypothesis that infants would display heightened sensitivity
to pitch-peaked and utterance-final words was also evaluated by calculating how many of
the infants' words in the 15-month sample had been previously spoken by their mothers
in isolation or utterance-final position or on either focally stressed or non-focally stressed
pitch peaks. Strong correlations were found to exist with all input variables except for
non-focally stressed pitch peaks, although several of the infants' words had not been
previously spoken by the mothers at all. These findings are then analyzed with respect to
their implications for the relationship between the prosodic characteristics of infantdirected
speech and the process of lexical acquisition. Limits on the generalizability of
these results and suggestions for future research are also discussed.