All over the world, when people talk to babies we all use a very similar tone of voice. We raise our pitch and change our intonation in ways that sounds happier and more excited. Researchers have found infant directed speech (IDS) has a distinctive change in vocal timbre that is similar across many languages. This appears to help babies learn language because they make it easier to separate individual words and make key vowel sounds more distinctive. Researchers agree that emotional content and intonation both matter when speaking to babies but the relative importance of these elements is not known.

The aim of the present study is to learn more about baby talk. We are working with JJ Aucouturier and his team from IRCAM, Paris who are specialists in emotion in music and speech signals in adults. They have developed audio filters that can manipulate the ‘smileyness’ and other emotional aspects of a speech signal. We will use their software to manipulate recorded speech and see what version babies prefer.

Click here to learn more about infant speech research.