Speech perception develops slowly through adolescence

What is it about?

We looked at the ability of school age children and adolescents (7-18 year olds) to perceive basic contrasts used in spoken language like the difference between /b/ and /p/ or between /s/ and /sh/. To achieve a more fine grained measure, we used a unique eye-tracking paradigm. In this paradigm listeners heard a common word (e.g., "beach"), and clicked on the corresponding picture from a screen containing a picture of the correct word, as well as a picture of a minimally different word ("peach") and words that didn't sound at all like the target word. In order to do this simple task, children have to fixate the pictures they are considering (so they can plan the motor movement), and these eye-movements can be launched very rapidly after the beginning of the word. Thus, the fixations can tell us what children are thinking before they have fully decided. We found that with this more sensitive measure, children showed continued development in these very basic speech perception abilities.

Featured Image

Why is it important?

The standard view in the field is that speech perception develops in infancy and there is a lot of data to support that. However, infants don't know many words and they can't produce speech, so as a result the kinds of learning mechanisms that can support the development of these auditory perception are highly limited. By showing an extended developmental window this raises the possibility of all sorts of new learning mechanisms that help children learn to perceive speech. For example, the onset of reading and spelling instruction could help organize the auditory system. Moreover, speech perception is a critical skill for early reading (children have to perceive small units of sound to map them to letters). If it is not fully developed by the time reading instruction starts, this may change how we teach reading skills.