Case Study

Imitating Vocalizations

ABA Therapy Case Study – 3-year-old boy

Portia Curriculum

Domain: Communication
Skill Category: Echoics


Many children with autism do not have an established echoic repertoire. Imitating vocalizations is an important skill for learning to communicate. Pairing procedures have been shown to increase vocalizations in some limited research studies, however, there is no evidence to suggest that pairing words with reinforcement reliably establishes echoic behavior. The study examined the use of two procedures to establish echoic behavior. The first procedure used items as a reinforcer for echoing in an attempt to use mand training to establish echoic behavior. The second procedure applied a promise of an edible reinforcement for echoing the label of a preferred picture. Both procedures used direct reinforcement for echoic behavior, however, the second procedure included the use of a promise of reinforcement prior to presenting the echoic and used edible reinforcement.

Background Information

The learner is a 3-year-old boy diagnosed with autism. He is currently receiving 12 hours of Intensive Behavioral Intervention  (IBI) per week. He has demonstrated free operant vocalizations such as ball and swing with clarity, however, he did not demonstrate any reliable echoic behavior. The purpose of the intervention was to establish echoic behavior with the overall goal of teaching him to mand and tact.


The study was conducted using a simple AB design. The first treatment procedure was manding with preferred items and the second condition was the use of edible items with a promise of reinforcement shown prior to the demand to echo using a visual (picture card) of a preferred item.

Baseline Data Summary

The baseline assessment was conducted using the VB-MAPP®. At the time of assessment the learner did not demonstrate any manding, tacting or echoic behavior.

Data Collection/Measurement

Data was collected on each trial and graphed as a percentage of successful echoics using the Portia Pro app.


The first procedure required the therapist to conduct a preference assessment prior to beginning the procedure. Once a variety of preferred items were identified the therapist would present each item with a verbal model for three opportunities. If the learner echoed during any of the three procedures he was given the item. If the child did not echo the item was removed and a new item presented.

During the second procedure the therapist presented a picture of a preferred item and at the same time held up a piece of chocolate brownie while presenting a verbal model for up to three opportunities. If the learner echoed during any of the 3 three trials he was given the brownie. If the learner did not echo the brownie was removed and a new trial was presented.

Both procedures were conducted three times per session for up to 10 minutes at a time or until the learner lost motivation.


During the first condition the learner echoed on average 11% of the time. In the second condition the child echoed on average 39% of the time with the last 7 sessions 78% on average.


The use of edible reinforcement as a promise, direct reinforcement in addition to a picture card increased this learner’s echoic behavior and spontaneous echoes significantly. It is hypothesized that the preferred items in the first condition were not motivating enough to evoke the behavior and a more valuable reinforcer was required. Furthermore, the use of a picture card and cue that the reward is available may have contributed to the results. When introducing teaching procedures that rely on the motivation of the learner it is very important to consider the potency of the reinforcer. Additionally, introducing visual cues may be an effective strategy when physical prompting is not possible in the case of echoic behavior.  Further intervention to fade the use of the promise, fade the picture card and generalize the procedure to manding and tacting behavior is in progress.


Tudor, R. M. (1999). Using Mand Training to Establish an Echoic Repertoire in Young Children with Autism. The Analysis of Verbal Behavior, 16, 29-44.

Esch, B.E., Carr, J.E., Michael, J. (2005). Evaluating Stimulus-Stimulus Pairing and Direct Reinforcement in the Establishment of an Echoic Repertoire of Children Diagnosed with Autism. The Analysis of Verbal Behaviour  21, 43-58.



Charlene Gervais, M.ADS, BCBA
Customer Support Manager

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