NCT02464527.

Trial name or title	Public title: Stimulus‐stimulus pairing study (SSP) Official title: A pilot feasibility study to increase vocal language in minimally verbal children diagnosed with autism spectrum disorders
Methods	Design: randomised, parallel assignment Duration of study: 6–12 weeks (intervention 6 weeks, control (wait‐list) wait 6 weeks and then receive the 6‐week intervention) Setting: Emory University
Participants	Sample size: 16 enrolled Sex: male and female children eligible for inclusion Age: range 24 months to 47 months Inclusion criteria: diagnosis of autism currently do not emit vocalisations or minimally verbal aged 24–47 months willingness of the participant's parent/guardian to bring their child to the Marcus Autism Center for 1‐h appointments, 5 days a week, for 6 weeks Exclusion criteria: children with significant problem behaviour that interferes with structured intervention
Interventions	Intervention: SSP, consisting of sounds and words being systematically paired with delivery of a preferred item Control: wait‐list control Administration: participants in the SSP l attend clinic‐based sessions for 1 h per day, 5 days per week, for 6 weeks. The SSP procedure will consist of sounds and words being systematically paired with delivery of a preferred item. The participants will be recorded by a vocal recorder by the parent/guardian at home or in the community.The wait‐list control group will wait for 6 weeks; children will not receive any treatment during this period. The wait‐list control group will then receive the SSP procedure (delayed procedure) after the 6‐week wait.
Outcomes	Primary outcomes Change in frequency of target vocalisations or approximations (or both) at home (time frame: week 1, week 6). Vocalisation data will be collected in the home via the vocal recorder device. Target vocalisation is when the participant emits the target sound or word. Change is defined as the difference in the number of vocalisations at week 1 and week 6. Change in parent‐reported vocalisations (time frame: week 1, week 6). A parent‐rated checklist will assess their child's vocal language, and parents will rate improvement as a yes or no question on the checklist at week 1 and week 6. Feasibility of intervention assessed by reliability of delivery by therapists (time frame: week 6). The number of times SSP is reliably delivered by the therapist to the participant during the intervention period of 6 weeks will be assessed. Reliable delivery consists of the therapist pairing sounds and words with preferred items in accordance to the protocol. Acceptability of SSP by parents (time frame: week 6). The level of compliance and willingness of the parents/guardian to bring the participants to the sessions will be assessed. Acceptability is when the parent/guardian brings the participant to the clinic for the sessions for 1 h a day, 5 days per week, for 6 weeks
Starting date	June 2014 Status: recruitment completed
Contact information	Name: Alice Shillingsburg Position: Assistant Professor Address: Emory University
Notes	Comment: further detail available at clinicaltrials.gov/show/NCT02464527 Funding source: Emory University

ADOS: Autism Diagnostic Observation Schedule; ASD: autism spectrum disorder; DTT: discrete trial training; JASP + EMT: Joint Attention, Symbolic Play, Engagement and Enhanced Milieu Teaching; SGD: speech generating device; SSP: stimulus‐stimulus pairing.