Speech treatment for children with Down Syndrome

This study of 51 children with Down Syndrome (ages 5–12) compared the treatment technique Broad Target Speech Recasts (BTSR) to a comparison technique, Easy Does It (EDI). They sought to improve speech comprehensibility, or “the extent to which an unfamiliar listener can understand what the speaker says (Hanson, Yorkston, & Beukelman, 2004)”. BTSR may be roughly described as a technique that uses primarily speech recasts* and doesn’t target specific phonological patterns, while EDI uses elicited imitation to target specific phonological patterns.
Results indicate that BTSR is superior to EDI in improving speech comprehensibility for students with DS who have above-sample-average verbal imitation skills (but still low comprehensibility), and that this effect is driven by cumulative number of speech recasts. The authors predict that this is because students with DS who have adequate verbal memory and motor capacity (decent verbal imitation skills in the first place) benefit from their SLP providing frequent correct speech models that they can immediately compare to their own productions.
The authors also spend some time explaining why speech comprehensibility (instead of, or in addition to, speech accuracy) should be a standard outcome measure for speech therapy. These authors also published another paper in this month’s JSLHR describing how to perform these measures reliably.

See: Yoder, P.J., Camarata, S., Woynaroski, T. (2016). Treating Speech Comprehensibility in Students with Down Syndrome. Journal of Speech, Language, and Hearing Research, 59(3), 446–459. 
*A speech recast is “an adult utterance that immediately follows a child’s 'platform' utterance, gives a neutral or positive evaluation of the meaning of the child’s utterance, and is an exact or reduced imitation of the word(s) that the child attempted to say but uses adult pronunciation”. e.g CHILD: “Da tu bid” ... ADULT RESPONSE: “That’s too big.”