Importance: The early language environment of a child influences language outcome, which in turn affects reading and academic success. It is unknown which types of everyday activities promote the best language environment for children.

Objective: To investigate whether the type of toy used during play is associated with the parent-infant communicative interaction.

Design, setting, and participants: Controlled experiment in a natural environment of parent-infant communication during play with 3 different toy sets. Participant recruitment and data collection were conducted between February 1, 2013, and June 30, 2014. The volunteer sample included 26 parent-infant (aged 10-16 months) dyads.

Exposures: Fifteen-minute in-home parent-infant play sessions with electronic toys, traditional toys, and books.

Main outcomes and measures: Numbers of adult words, child vocalizations, conversational turns, parent verbal responses to child utterances, and words produced by parents in 3 different semantic categories (content-specific words) per minute during play sessions.

Results: Among the 26 parent-infant dyads, toy type was associated with all outcome measures. During play with electronic toys, there were fewer adult words (mean, 39.62; 95% CI, 33.36-45.65), fewer conversational turns (mean, 1.64; 95% CI, 1.12-2.19), fewer parental responses (mean, 1.31; 95% CI, 0.87-1.77), and fewer productions of content-specific words (mean, 1.89; 95% CI, 1.49-2.35) than during play with traditional toys or books. Children vocalized less during play with electronic toys (mean per minute, 2.9; 95% CI, 2.16-3.69) than during play with books (mean per minute, 3.91; 95% CI, 3.09-4.68). Parents produced fewer words during play with traditional toys (mean per minute, 55.56; 95% CI, 46.49-64.17) than during play with books (mean per minute, 66.89; 95% CI, 59.93-74.19) and use of content-specific words was lower during play with traditional toys (mean per minute, 4.09; 95% CI, 3.26-4.99) than during play with books (mean per minute, 6.96; 95% CI, 6.07-7.97).

Conclusions and relevance: Play with electronic toys is associated with decreased quantity and quality of language input compared with play with books or traditional toys. To promote early language development, play with electronic toys should be discouraged. Traditional toys may be a valuable alternative for parent-infant play time if book reading is not a preferred activity.