Title: Influence of infants on maternal speech and singing
Authors: Judy Plantinga (University of Toronto), Sandra E. Trehub (University of Toronto/
BRAMS), Frank Russo (Ryerson University, Toronto)
Introduction
When mothers vocalize to their infants by talking and singing, they provide infants with a rich
multimodal experience. To date, however, attention has focused largely on the vocal aspects of
that experience. Infants not only hear their mothers’ voice but they also see her accompanying
movements and gestures. Presumably, multimodal aspects of mothers’ sung and spoken
performances are also affected by the infant’s ongoing responsiveness. We investigated how
the expressiveness of mothers’ speech and singing to infants was altered when the partners
could hear but could not see one another. In one condition, mother and infant had full visual
access to one another. In a second condition, visual access was removed from both parties. In a
third condition, the mother could monitor her infant by means of a video feed, but the infant
could not see the mother. Each of these episodes was a minute in duration. If maternal singing
and speech are influenced primarily by the mother’s intention to maintain her infant’s
engagement, then one would expect the mother to generate more expressive (i.e, work harder)
when her infant is out of view. If, however, mothers’ vocal performances depend critically on
feedback from the infant, then one would expect more expressive maternal performances when
the infant is in view. All data have been collected and are currently being coded for expressive
vocal and gestural features in the three conditions. A preliminary review of the data suggests
that access to infants’ behavior contributes to the enhancement of maternal vocal and gestural
expressiveness. The study is consistent with the objectives of Theme 1 (Development of
singing and comparisons with speaking), in particular, with Subtheme 1.1 (Multimodal
Analysis), under the supervision of subtheme leaders Sandra Trehub and Frank Russo.
 
Bios
Judy Plantinga is a postdoctoral fellow in Dr. Sandra Trehub’s Auditory Development Lab at
University of  Toronto. She earned her PhD in Psychology, Neuroscience, and Behaviour from
McMaster University. Her main area of interest is the development of pitch perception and its
relation to the development of music and language abilities. Web page: http://
www.utm.utoronto.ca/11587.0.html
Frank Russo is Assistant Professor of Psychology, Director of Psychological Science
Training and Director of the Science of Music, Auditory Research and Technology (SMART)
lab at Ryerson University. After earning his Ph.D. from Queen's University at Kingston
(2002), he was awarded the Shaw Post-Doctoral Prize in Acoustics (Canadian Acoustical
Association) and completed Post- Doctoral Fellowships in Music Cognition and Hearing
Science. His research is situated at the intersection of music, mind and technology with current
projects investigating multisensory integration, assistive technology, sonification,
electrophysiological response, and the role of mimicry in communication of emotion (see lab
website for more info, http://www.ryerson.ca/smart). He has published over 20 peer-reviewed

 articles and has delivered over 100 presentations. Other notable work includes consultation
with U.S. and Canadian Departments of Transportation on Locomotive Horn Effectiveness,
and co- invention of a sensory substitution technology supporting perception of music by deaf
and hard of hearing individuals (Emoti-Chair). Frank currently serves on the editorial board of
Psychomusicology: Music, Mind and Brain and the board of directors of the Canadian
Acoustical Association and the Society for Music Perception and Cognition.
After undergraduate studies in Economics and Philosophy, Sandra Trehub pursued graduate
studies in Psychology at McGill University, receiving her doctorate in 1973. Since that time,
she has been at the University of Toronto, where she is currently Professor Emeritus of
Psychology. Professor Trehub has published extensively on auditory perception in infants and
young children, infants' perception of music, and parents' songs to infants. Most of her
research is conducted in her laboratory at the University of Toronto (http://
www.utm.utoronto.ca/11558.0.html. From time to time, however, she visits isolated villages
around the world to observe mothers' use of music in the course of child care.