A simultaneous treatment comparison of three expressive language training programs with a mute autistic child.

One mute young learners with autism took part. The team ran three language trainings side-by-side in an alternating-treatments design.

Sessions were sign-only, speech-only, or total communication (sign plus spoken word). The child earned the same toy for any correct response.

Total communication won by a mile. The boy reached 20 new words in 14 sessions, twice as fast as sign-alone and four times faster than speech-alone.

Signs paired with spoken words also stayed strong at a two-week check.

Burgess et al. (1986) later copied the sign-plus-speech edge in kids with intellectual disability, showing the boost holds even when autism is not part of the picture.

Abdi et al. (2023) now supersedes the 1980 work. Their 16-session multi-theory package gives even bigger vocabulary gains, thanks to four decades of fine-tuning.

Doherty et al. (2018) looks like a clash at first—they used PECS pictures, not signs. Yet both studies show the same lesson: give the child two ways to reach you (picture or sign plus word) and expressive language grows faster.

If you have a non-vocal preschooler on your caseload, pair every new sign with its spoken word from day one. This old trial and its replications say the dual cue cuts learning time in half, and newer packages keep raising the bar. Start with total communication now, then layer in later refinements as needed.