Application of nonlinear phonological theory to intervention with six phonologically disordered children

The purpose of this investigation was to examine the utility of nonlinear phonological frameworks for designing and executing an intervention program with phonologically disordered children. Six such children between the ages of 3 and 6 years participated in the study three times a week over three consecutive six-week blocks. The following general questions were addressed: 1. Will nonlinear phonological frameworks help to predict logical and attainable intervention goals for phonologically disordered children? 2. Are the separate prosodic and segmental levels of representation of nonlinear phonology psychologically real? 3. If the 'prosodic tier' has some observable clinical reality, will there be a difference in proportion and rate of syllable/word shapes acquired as a result of intervention methods that contrast the onset and rime versus those that utilize the mora a constituent? 4. If the 'segmental/melodic tier' has some observable independence, is there any advantage to be gained from targeting specified features at 'higher' versus lower' levels in the feature hierarchy in phonemic inventory intervention? An alternating block, mulitiple baseline design (counterbalanced over six single subjects) provided an opportunity to investigate the above questions. Within each six-week block, three week periods were devoted in turn to prosodic (syllable structure) training and segmental training. Prosodic subblocks were divided into two four-session sunblocks to contrast developmental change for targets presented as moraic constituents versus onset-rime constituents. Segmental periods were divided into two four-session subblocks to contrast developmental change for features from higher and lower levels in the feature hierarchy. Analyses during and after the study demonstrated the following with respect to the four research questions: 1. The nonlinear frameworks provided a logical model for deriving attainable intervention goals. All of the children became intelligible by the end of the project as a result of attaining the goals determined by nonlinear phonological theory. 2. Rate of attainment of syllabic and segmental goals differed, with a faster rate of change for syllabic goals overall, suggesting independence of segmental and prosodic tiers, and possible dominance of the prosodic tier. Interactions between tiers were also observed, suggesting that they are interdependent as well as autonomous. 3. Moraic and onset-rime condition quantitative results were virtually equivalent, but some qualitative differences appeared which had relevance for the each of the theories with respect to status of the onset, word-final consonants, and epenthesis. 4. Higher level features in the feature hierarchy tended to be acquired before lower level features. The nonlinear phonological frameworks stimulated a successful intervention study. Evidence gained through this study in turn contributes to the understanding of the nonlinear constructs.Medicine, Faculty ofAudiology and Speech Sciences, School ofGraduat