A study of 98 children, 9 to 14 years old, compared three types of stuttering therapy. The three types of therapy were:
- Intensive “smooth speech” fluency shaping therapy trained relaxed, diaphragmatic breathing; a slow speaking rate with prolonged vowels; gentle onsets and offsets (loudness contour); soft articulation contacts; and pauses between phrases. The children did this therapy in a speech clinic for 35 hours over the course of one week.
- Home-based “smooth speech.” This was similar to the first group, but parents were included; the children and parents were encouraged to continue therapy at home. Therapy was done in a speech clinic for six hours once a week for four weeks (24 hours total).
- Electromyographic biofeedback. The children used an EMG biofeedback computer system for about six hours a day for five days (30 hours total). The EMG system monitored the child’s speech-production muscle activity. The children were instructed to tense and then relax their speech-production muscles. The goal was to develop awareness and control of these muscles. The children then worked through a hierarchy from simple words to conversations, while keeping their speech-production muscles relaxed. After mastering this while watching the computer display, the children did the exercises with the computer monitoring but not displaying their muscle activity. The speech-language pathologists did relatively little with the children: “Constant clinician presence was not necessary as the computer provided feedback as to whether the child was performing the skills correctly.”
- A fourth (control) group didn’t receive any treatment.
At the end of each therapy program, all three therapies reduced stuttering below 1% on average. The control group had no improvement in fluency.
One year after the therapy program, the percentage of children with disfluency rates under 2% were:
- 48% of the children from the clinician-based program.
- 63% of the children from the parent-based program.
- 71% of the children from the computer-based program.
The results for children with disfluency rates under 1% were even more striking:
- 10% of the children from the clinician-based program.
- 37% of the children from the “parent-based” program.
- 44% of the children from the computer-based program.
In other words, the computers were most effective, the parents next most effective, and the speech-language pathologists were least effective in the long term. At the 1% disfluency level, the computers and the parents were about four times more effective than the speech-language pathologists.
Four years later, all three groups had average stuttering reductions between 76% and 79%. This may have been due to the more disfluent children receiving additional speech therapy.