Are you talking to ME? Tagging speech to children and adults

When we speak to infants and children, we tend to modify the way we sound, for example by simplifying vocabulary, and changing pitch and speed. This has been called child-directed-speech. While we know many of the characteristics of child-directed-speech (shorter utterances and more positive affect, also more variability in pitch and pitch contour compared to adult-directed speech), we know less about how much child- vs. adult- directed speech infants and children hear in their daily environments, and whether this varies across different speakers in the environments.

In a previous research study, we had North-American 6-17 month old infants wear vests with recorders attached to them, so that we could record everything they heard in a single day. The recording software gives us information such as who was speaking (male adult, female adult, child, etc) and approximately how many words they said, which gives us a general snapshot of the language a child is hearing. However, the recorder can’t differentiate between speech addressed directly to the child or speech addressed to other adults in the environment. As volunteers in this research study, you will help us determine which sound clips sound like they were directed at the child, and which ones sound like they were directed at other adults. Based on your ratings, we are looking forward to answering questions such as:
• What proportion of speech overall is child-directed vs. adult-directed?
• What proportion of speech from primary caregivers (e.g. mom, dad) is child-directed vs. adult-directed?
• Does hearing more child-directed speech lead to infants hearing more variable speech (based on other acoustic metrics)?