Effects of mother's imitation on speech sounds in infants with Down syndrome

Background: The Down syndrome behavioral phenotype includes delays in making speech sounds, production of more non-speech sounds than speech sounds, and contrasting strengths in social development. Within a behavior analytic framework, we conceptualize characteristics of the Down syndrome behavioral phenotype as creating a context for impairments in speech sound development that suggest interventions caregivers can use to improve speech sounds. Aim and method: We examined one intervention, the effects of mother's contingent vocal imitation, on rate of speech and non-speech sound production in infants with Down syndrome using an ABAB design. Results: Mothers responded favorably to learning to imitate their infants' vocalizations and their contingent vocal imitation was associated with increases in infant speech sounds. Conclusions: The increases in infant speech sound suggest the promise of this approach and future research examining variations in contingent vocal imitation and additional outcomes.