RESUMEN
PURPOSE: The purpose of this study was to report on modifications we made to a standardized input-based word learning treatment for two late-talking toddlers. The modifications were the addition of an augmentative alternative communication (AAC) device and the requirement that the children use this device, or speech, to communicate. METHOD: We used a single-subject design to track late-talking toddlers' progress through an input-based word learning treatment, which was part of a larger study. Because the input-based treatment protocol was not effective for each toddler based on absent or clinically insignificant treatment effect sizes, we modified the protocol. The modifications were meant to address each child's potential over-reliance on nonverbal communication and the potential impact of speech sound delay. We then measured their linguistic output. RESULTS: Both toddlers showed no evidence of learning during the input-based treatment. Each child's linguistic output increased by over 600 % once we made the protocol modification and introduced the AAC device. They used both AAC and vocal speech to communicate. Both toddlers produced novel words, and one began to produce multiple word combinations. DISCUSSION: While input-based therapy has an evidence base and has been successful for some toddlers, it may require modifications for children who have not learned the pragmatic convention of using spoken language, and for children with difficulty with speech sound production.