Infant-Directed Speaking and Singing:
New Evidence from Eyetracking
Petra Hauf & Sara Murphy
St. Francis Xavier University
Antigonish, NS, Canada

This research is funded by grants from AIRS (SSHRC), CFI, and the CRC program awarded to Petra Hauf.

 Introduction
Research on vocal interaction has accumulated the
notion of an infant-directed (ID) register.
• ID-Speaking
– is characterized by heightened pitch, distinct and exaggerated
pitch contours, and slower tempo.
– may promote attention and efficient learning.

• ID-Singing
– is characterized by heightened pitch, slower tempo, and a
regulated pulse.
– may facilitate emotional communication and arousal
regulation.

 Introduction
• To further investigate infants’ responsiveness to these
two vocal styles, the present series of studies …
… introduced eyetracking to
monitor
infants’ looking
behaviour.
… presented a standardized,
maternal source engaged
speaking and ID-singing.

nonin ID-

 Study I & II
• Participants
– Study I: 24 infants (12 female) between 5;13 and 7;06 months
of age (M = 6 months,13 days);
– Study II: 24 infants (12 female) between 10;15 and 12;03
months of age (M = 11 months, 17 days.

• Procedure
– Infants watched two short videos (48 sec each) of an adult
engaging in ID-singing and ID-speaking
– Infants received one of two conditions:
 Familiar lyrics (Itsy Bitsy Spider)
 Novel lyrics (Baby Duck)

 Results
Looking Time (sec)

50
40

Overall Looking Time

ID-Singing

ID-Speaking

30
20
10
0
Familiar Lyrics Novel Lyrics Familiar Lyrics Novel Lyrics

6-month-olds

12-month-olds

 Results
Looking Time (%)

100

Familiar Lyrics
75

Mouth
Eyes

50
25

0
ID-Singing ID-Speaking ID-Singing ID-Speaking

6-month-olds

12-month-olds

 Results
Looking Tme (%)

100

Novel Lyrics
75

Mouth
Eyes

50
25
0
ID-Singing ID-Speaking ID-Singing ID-Speaking

6-month-olds

12-month-olds

 Study III
• Impact of melody and rhythm on infants’ perception of
ID-Speaking and ID-Singing
– Here we are presenting 6-month-olds with videos contrasting
familiar and novel lullabies.
 Familiar lyrics (Rock a bye Baby)
 Novel lyrics (The Moon has Risen)
– Question: Will differences in melody and rhythm lead to
differences in looking behaviour compared to the play songs
of Study I?

 Study IV
• Impact of melody and rhythm on infants’ perception
of ID-Speaking and ID-Singing
– Here we are presenting 6-month-olds with videos
contrasting exhilarating ID-speaking and calming IDspeaking.
– Question: Will distinct features in rhythm lead to
differences in looking behaviour compared to the
exhilarating ID-singing and calming ID-singing of Study I
& III?

 Study V
• Impact of source familiarity on infants’ perception of
ID-Speaking and ID-Singing
– Here we are presenting 6-month-olds with live videos,
contrasting their mothers and a stranger engaging in IDspeaking and ID-singing.
– Question: Will infants show higher overall engagement when
presented with a familiar source compared to a stranger and
will ID-speaking and ID-singing be affected equally?

 Acknowledgement
• Parents and Infants participating in the study.

• Researchers conducting this project
– Trisha Brosha
– Charlene Parker, Sara Murphy
– Jamie Harris, Ali Butler, Ruth Hofrichter, Jeff Foshay

• Funding enabling this research
– AIRS (SSHRC)
– CFI and CRC program