Mothers versus others: Caregiving experience influences perception of infant vocalizations
Rachel Albert, Lily Molik, Haley Roenneburg, Jena VanderLogt, Emily Lindberg, & Rebecca Pletka
University of Wisconsin-Stevens Point
Background
Caregivers’ responses to infant babbling have long-term
effects on infant language learning.
•  Caregivers consistently provide feedback to infants’
prelinguistic vocalizations (Goldstein & West, 1999).
•  Maternal responsiveness to vocalizations in the first two
years predicts later language development (TamisLeMonda, Bornstein, & Baumwell, 2001).
What factors influence caregivers’ responding?
•  Studies on adults’ perceptions of cries have found
experience related differences between parent and nonparents (e.g. Green, Jones, & Gustafson, 1987).
•  Mothers rate the qualities of babbles and respond
differently to infant vocalizations than non-mothers (Albert,
Schwade, & Goldstein, under review; See Figure 2 for
replication).
•  Caregiving experience appears to be one factor that
influences when and how caregivers respond to infant
vocalizations.
What is the effect of caregiving experience on nonmothers’ responsiveness to babbling?
•  Experienced non-mothers (i.e. daycare workers) and
inexperienced non-mothers rated and responded to infant
vocalizations via a playback paradigm to assess the
influence of caregiving experience on responding.
Method
Summary of Findings
Participants: 30 female participants (mean age=20.63
years, range=18-25) were classified as inexperienced (n=15)
or experienced caregivers (n=15). Experienced caregivers
were currently employed at a daycare working with children
under age 2 (mean=12.5 hrs/wk, range = 3-40 hrs/wk).
Procedure: Participants provided an in-the-moment vocal
response to 80 audio-visual examples of infant vocalizations
(Figure 1). They also rated each vocalization on a 7-point
Likert ‘speechiness’ scale with ‘1’ being least speech-like and
‘7’ being most speech-like.
Stimuli: Each stimulus consisted of a 7 second video of an
unfamiliar 9-month-old infant coupled with a prelinguistic
vocalization. Infants were in the act of playing and
vocalizing. The stimulus clips were created by recombining
audio and visual images of infant behavior on two
dimensions: Infraphonology (Table 1) and Directedness
(Figure 1).
Data Analysis: The mean speechiness rating for each
infraphonological syllable type was calculated for each
participant. Participants’ vocal responses were coded into
one of five categories (Table 2).
Ah
Ah
Ba
Object Directed Vocalizations
•  Caregiving experience does not appear to significantly
influence non-mothers perceptions of infant vocalizations.
Ba
Undirected Vocalizations
Figure 1. Sample images of stimulus clips. Paired clips allowed for
assessing the effects of the four syllable types, and the effects of
changing the direction of the vocalization (object directed, undirected).
Syllabus Type Description Example Quasi-resonant
vowel (QRV) Vowel produced with a closed vocal
tract, resulting in nasalized vocalizations [grunt] Fully-resonant
vowel (FRV) Vowel produced with an open vocal tract [ah] Marginal Syllable
(MS) Slow sequences of consonant–vowel
articulation [bwaa] Canonical
Syllable (CS) Fast consonant-vowel transitions with a
FRV [ba] Table 1. Prelinguistic vocalizations were categorized by their acoustic
properties using an infraphonological coding system (Oller, 2000). Speech Ratings
Comparison of Inexperienced and Experienced
Non-Mothers
•  Eliminates the personal interaction dynamics (i.e.
idiosyncratic history) a caregiver has with a specific infant.
The playback paradigm elicits natural responses.
•  Mothers show nearly identical patterns of responses
whether responding to their own infant in a live play
session or to videos of unfamiliar infants in the playback
paradigm (Albert, Schwade, & Goldstein, under review).
2.  Are the perceptual differences in speech ratings between
mothers and non-mothers explained by age more than
caregiving experience?
4.  Do similar perceptual differences exist between fathers
and non-fathers?
Figure 2. Mean speech maturity rating for each infraphonological
type (±1 SE) by parity group. * p <.05. Note: Mother data (green)
from Albert, Schwade, & Goldstein (under review).
Figure 3. Mean speech maturity rating for each
infraphonological type (±1 SE) by experience group.
Influences of Caregiving Experience on Non-Mothers’ Responses to Infant Vocalizations
Benefits of using a playback paradigm:
•  All participants are exposed to the same set of highly
controlled stimuli.
•  Currently testing a group of full-time daycare
employees in infant classrooms.
3.  Does childbirth reorganize women’s perceptions of infant
vocalizations?
What is a playback paradigm?
•  Playback paradigms are commonly used in non-human
animal research to assess how specific visual or auditory
behaviors of one animal influence the behavior of another.
Future directions
•  Currently comparing an age-matched group of nonmothers and mothers.
Background on Methodology:
Playback Paradigm
•  A method used to expose participants to prerecorded
stimuli and measure participants’ responses to each
stimulus.
Playback paradigm
1.  Can we better define caregiving experience to determine
how much exposure to infant vocalizations equates to
experience?
Results
Comparison of Mothers and Non-Mothers
•  Caregiving experience does predict some differences in
how non-mothers respond to infant vocalizations. For
example, inexperienced non-mothers ask more questions
than experienced non-mothers when responding to
vowels.
Response Type Definition Example Question Questions about the infant’s state or
current actions
What do you
have? Description Statements that describe the infant,
infant’s action, or objects near infant
That’s a ball. Affirmation Words that hold a place in the
conversation without providing new
information Uh-huh,
I know Play Prompt Imitation +
Albert, R.R., Schwade, J.A., & Goldstein, M.H. (under review).
Understanding parenting from the infant’s perspective: New methods
reveal new influences on responsiveness to infant behavior.
Goldstein, M.H., & West, M.J. (1999). Consistent responses of human
mothers to prelinguistic infants: The effect of prelinguistic repertoire
size. Journal of Comparative Psychology, 113, 52-57.
Green, J.A., Jones, L.E., & Gustafson, G.E. (1987). Perception of cries by
parents and nonparents: Relation to cry acoustics. Developmental
Psychology, 23, 370-382.
Oller, D. K. (2000). The emergence of the speech capacity. Mahwah, NJ:
Erlbaum.
Prompts that guide an infant to perform an Roll me the ball! action
Duplications of the infant’s vocalization References
Tamis-LeMonda, C.S., Bornstein, M.H., & Baumwell, L. (2001). Maternal
responsiveness and children’s achievement of language milestones.
Child Development, 72, 748-767.
Baby: [ba];
Mom: [ba] Note: adapted from Tamis-LeMonda et al., 2001 Table 2. Coding system used to categorize caregiver speech. Figure 4. Mean proportion of vowel vocalizations that
received each response type (+1 SE) by experience group.
+ p =.055.
This research was supported by a
UWSP UPDC Grant to RRA and
UWSP URSCA travel grants to all
presenters.
Contact information:
Rachel Albert
University of WisconsinStevens Point
ralbert@uwsp.edu