Japanese mothers' use of specialized vocabulary in infant-directed speech: Infant-directed vocabulary in Japanese
When adults talk to infants or young children, they modify their speech. The specialized speech is sometimes called motherese or infant-directed speech (IDS). Many characteristics of IDS have been documented across many languages, but the best known characteristics of IDS have to do with prosody of the speech, such as higher pitch and exaggerated pitch contours, and longer more frequent pauses (c.f., Fernald and Simon 1984; Fernald and Kuhl 1987; Fernald and Mazzie 1991; Snow and Ferguson 1977). Other types of modifi cations also occur, such as changes in syntactic properties, e.g., shorter and simpler utterances, and semantic contents, e.g., conversation about here and now (c.f., Newport et al. 1977). It has often been argued that many of the IDS properties are universal (Fernald 1993; Fisher and Tokura 1996; Grieser and Kuhl 1988; Kuhl and et al. 1997; Trainer and et al. 2000), but there are signifi cant cross-linguistic variations in the way mothers interact with their infants (e.g., Fernald and Morikawa 1993), and the way adults modify their speech in IDS (Fernald et al. 1989).
