A multi-modal approach to intervention for one adolescent's frontal lisp

An adolescent with a persistent frontal lisp participated in a two-part 11-session intervention case study. The first phase used ultrasound imagery and acoustic, phonetic and voice education to provide information about articulatory setting (AS) and general awareness of the speech production process. The second phase used traditional articulation therapy, online visual-acoustic biofeedback and fluency strategies to target the frontal lisp directly (specifically /s/, /z/, /ʃ/ and /ʧ/). Trained listener evaluations of pre-intervention, post-phase 1 and post-phase 2 assessments showed no improvement after phase 1, but notable improvement in all treatment targets immediately after phase 2. These improvements were substantially maintained at assessment 4 months post-intervention. The outcomes suggest that direct training was more effective than the AS approach; however, the client's ability to self-monitor in phase 2, rapid acquisition of the targets and maintenance at 4 months post-intervention possibly reflected the knowledge gained in phase 1 about AS.