Onomatopoeia in Infant Directed Speech
The study in a sentence
This study examined the acoustic phonetic properties of onomatopoeic words (quack) produced by caregivers to babies and found that they were much more salient than their conventional counterparts (duck), making them more easily learnable for babies.
Onomatopoeia make up a large proportion of the early words produced by children (20-40% in different studies and different languages), but they are often left out of the analysis as unimportant.
This study looks turns things around to look at the input to babies - that is, the speech that they hear from the adults around them. The study investigates the details of how onomatopoeia are produced in recordings of adults talking to babies, to see whether these words may stand out more to the babies.
If a word or phrase is prosodically salient it has been pronounced with one or more prosodic features that make it stand out from the surrounding talk to the hearer. Prosody refers to phonetic features that are realised across stretches of speech (such as syllables, words and phrases) rather than on an individual speech sound (such as a consonant or vowel).
In English, a syllable can be made to stand out within a word by making the syllable longer and/or louder (word stress). A word can be made to stand out within a phrase by producing the word with a pitch contour with a clear shape - such as a fall or rise - as well as by expanding the pitch range or using higher pitch on that word (sentence stress).
Do onomatopoeic words stand out in infant-directed speech?
Methods: analysing pitch
Speech analysis software can be used to visualise the shape of the pitch contour on an utterance.
Watch this video by Richard Ogden to learn how to perform some simple pitch contour analysis.
The video uses Praat software which is freely available to download. If you want to try using Praat yourself there are a series of tutorials that you can work through starting from basic tasks such as how to open up sound files for analysis.
Pitch contour of HORSE produced in Infant Directed Speech
Figure 5c from: Laing, C. E., Vihman, M., & Keren-Portnoy, T. (2017). How salient are onomatopoeia in the early input? A prosodic analysis of infant-directed speech. Journal of Child Language, 44(5), 1117–1139. download
Onomatopoeic words, such as boing and woof, were found to be acoustically more salient than their conventional counterparts (e.g. ball and dog) in several ways. Onomatopoeic words are often:
Higher in pitch
Wider in pitch range
Longer in duration
Reduplicated (woof woof)
Spoken in isolation
These prosodic features are not unique to onomatopoeia. In fact, they are commonly used in speech when caregivers address infants, capturing their attention and facilitating language learning.
The finding that caregivers produce onomatopoeia with even more exaggerated features may be a reason why these words are among those acquired the earliest by infants.