Date of Award


Document Type


Degree Name

Doctor of Philosophy (PhD)


Communication Sciences and Disorders

First Advisor

Hugh W. Buckingham


The Sonority Sequencing Principle suggests that the relative sonority rank among sounds can explain intrasyllabic and transsyllabic phoneme ordering patterns in normal speakers. The values of segments can be ranked from most to least sonority as follows: Vowels, Glides, Liquids, Nasals and Obstruents. The unmarked order of segments within an initial demisyllable is O-N-L-G from the periphery toward the peak, and G-L-N-O in a final demisyllable from the peak toward the periphery. The sonority "slope" of an initial demisyllable will be steep to maximize the perceptual saliency of syllable onset. In a final demisyllable, especially if embedded, the slope will be flatter to maintain sonority contrast between abutting syllables. This study answered the following questions: (1) What syllable shape and sonority profile patterns (in four types of demisyllables) are present in the neologistic and legitimate English utterances of three fluent aphasics, (2) Are these patterns similar to those observed in the well-formed utterances of normal speakers, (3) Does the sonority principle facilitate neologism analysis, (4) Can sonority be incorporated further into models of sentence production and, (5) What implications for sonority theory and for theories of neology are suggested by results. Data from three neologistic jargonaphasics were audio-recorded during expressive language tasks. Neologisms were phonemically transcribed by three independent listeners. A demisyllable data base for target-related neologisms, abstruse neologisms, and English words was compiled for each subject. Summary frequency distributions for demisyllable shapes and sonority profiles were obtained and tested for each word type. Results from extensive demisyllable analyses suggested the following: (1) demisyllable shapes for neologisms and English words were most often of the form CV or CVC, (2) intrasyllabic and transsyllabic sonority profiles in neologisms and English words were most frequently of the preferred patterns, although some exceptions were noted, (3) demisyllable shapes and sequence preferences were similar to patterns found in legitimate English words and, (4) sonority may constrain the operation of mechanisms that create neologisms, whether viewed from a serial or parallel model of language production. Results suggest that sonority may partially govern construction of normal and impaired phonological forms.