Learning the meaning of “um”

Previous research has uncovered various contextual and social cues that children may use to infer speakers' communicative intentions (e.g. joint visual attention, pointing). We review evidence from eye-tracking studies that suggests that by 2;6 years of age, children use another previously unexplored cue to infer speakers' communicative intentions: speech disfluencies. Disfluencies (e.g. “uh” and “um”) often occur before unfamiliar, infrequent, and discourse-new words. Thus, disfluencies provide information about a speaker's intended referent. Further children use the presence of a disfluency before an object label to anticipate a novel, discourse-new referent. These results demonstrate that children go beyond their input, acquiring the generalization that disfluencies precede not just specific words, but rather categories of words that are difficult to produce. Keywords: Language acquisition; speech disfluencies; lexical development; eye-tracking; attention