Infant-Directed Speech in the UK and US

The study in a sentence

Before babies can learn words, they have to be able to recognise where words begin and end in the speech that they hear around them. This study raises the possibility that known differences between the typical properties of Infant Directed Speech in American English versus British English may explain the fact that UK babies typically display ability to recognize words in running speech later than US babies. We also suggest other ways to interpret the findings of this study.  

Pitch contour in one of the exaggerated IDS samples played to babies.Floccia et al. (2016). Figure 1

The question

Researchers on child language development use the term infant to describe a child who is not yet speaking or producing any language, i.e. babies under the age of 18-24 months. 

Infant Directed Speech (IDS) is known to have a specific set of properties, such as more varied and expanded use of pitch.  Previous research has shown that there are differences between the IDS produce by caregivers who are speakers of American versus British English. This study explores whether these differences in the properties of IDS have an impact on babies' language development.

Key concept

Word segmentation is the task of identifying where words begin and end in the continuous stream of sound that we hear when we listen to speech. If you listen to speech in a language which you don't know, it can be difficult, if not impossible, to say where one word ends and another word begins. Successful word segmentation is a necessary step on the way to learning new words; to learn words, and to recognise the words we have learned in others' speech, we need to know which sequences of sounds are possible words.

Do differences in the properties of US and UK Infant-Directed Speech matter? 


How can we work out which words babies do or don't recognise?

The Head-Turn Preference procedure is a well-established method of measuring what babies and infants pay attention to. The video explains how the procedure works.

Chart listing the results of fourteen different studies testing babies ability to segment words in running speech, with only one positive result.
Results of 14 studies testing babies' ability to segment words in running speechAdapted from Floccia et al (2016) Table 1

The answer

The authors of this study between them carried out fourteen (14!) different studies with babies in the UK and the USA, but babies displayed ability to segment words in running speech in only one study.   This contrasts with findings of earlier studies in which babies of the same age or younger learning American English and several other languages did display ability to segment words     

Try segmenting words in an unfamiliar language yourself in the isolated words case study.

The one study which showed a positive result for British babies used recordings of IDS which had much more exaggerated features than is typical for IDS produced by British English speakers. 

Classroom activities

Lead in task

Is it ADS or IDS?

Extension task

Listening more closely to IDS - is it always the same?

In more detail

A longer explanation of the research study

Recommended order:
TKP Part 1 slides.pptx
TKP Part 2 slides.pptx
TKP Part 3 slides.pptx

Meet the author

Tamar Keren-Portnoy

Tamar teaches modules on Language Acquisition, Structure of Language and A Usage-Based View of Language.
Thanks to Heather Turner for developing the teaching materials for this case study. 

Read the paper

Floccia, C., Keren-Portnoy, T., DePaolis, R., Duffy, H., Delle Luche, C., Durrant, S., ... & Vihman, M. (2016). British English infants segment words only with exaggerated infant-directed speech stimuli. Cognition, 148, 1-9. download pdf