Daniel A. Dinnsen

Generative phonology : description and theory

Preliminaries Phological Rules and Representations Alternations Phonological Sketches Evidence and Motivation The Problem of Abstractness The Representation of Sounds Rule Interaction Notation The Role of Syntax and the Lexicon in Phonology References Language Index Subject Index

Statistical analysis of word-initial /k/ and /t/ produced by normal and phonologically disordered children

The acoustic characteristics of voiceless velar and alveolar stop consonants were investigated for normally articulating and phonologically disordered children using spectral moments. All the disordered children were perceived to produce /t/ for /k/, with /k/ being absent from their phonetic inventories. Approximately 82% of the normally articulating childrens consonants were classified correctly by discriminant function analysis, on the basis of the mean (first moment), skewness (third moment) and kurtosis (fourth moment) derived from the first 40 ms of the VOT interval. When the discriminant function developed for the normally articulating children was applied to the speech of the phonologically disordered group of children, no distinction was made between the velar and alveolar stops. Application of the model to the speech of individual children in the disordered group revealed that one child produced distinct markings to the velar-alveolar contrast. Variability measures of target /t/ and /k/ utteranc...

Consonant Clusters in Disordered Speech: Constraints and Correspondence Patterns.

Comparison of patterns of cluster realization from 47 children ranging in age from 3;4 to 6;8 with functional (non-organic) speech disorders with those reported in the literature for normal acquisition reveals that these patterns are essentially the same for both groups. Using a two-level generative phonology for childrens independent systems, further analysis of cluster realizations by means of feature geometry and underspecification theory reveals that there are systematic and principled relationships between adult representations of clusters and childrens underlying representations and between childrens underlying representations and their phonetic representations. With special emphasis on coalescence phenomena, it is suggested that the apparent diversity in childrens cluster realizations can be reduced to four constraints on the form of underlying and phonetic representations.

The effect of substitution patterns on phonological treatment outcomes

It has been suggested that phonological learning in children with articulation disorders is influenced by the variability or consistency of substitutes used for sounds that are excluded from the inventory. This proposal was based on a post-hoc analysis of childrens pre-treatment inventories and substitution patterns, as well as their generalization patterns at the termination of phonological intervention. In the present investigation, an experimental treatment study was conducted as a direct test of a hypothesized relationship between substitution variation and treatment outcomes. Ten children with multiple articulation errors were divided into two groups on the basis of the variability or consistency of their substitutes for sounds that were omitted from their phonetic inventories. The first group (consistent substitute; CS) of children used the same substitute for the omitted sound in all word-positions, whereas children in the second group (variable substitute; VS) varied the substitute within and acr...It has been suggested that phonological learning in children with articulation disorders is influenced by the variability or consistency of substitutes used for sounds that are excluded from the inventory. This proposal was based on a post-hoc analysis of childrens pre-treatment inventories and substitution patterns, as well as their generalization patterns at the termination of phonological intervention. In the present investigation, an experimental treatment study was conducted as a direct test of a hypothesized relationship between substitution variation and treatment outcomes. Ten children with multiple articulation errors were divided into two groups on the basis of the variability or consistency of their substitutes for sounds that were omitted from their phonetic inventories. The first group (consistent substitute; CS) of children used the same substitute for the omitted sound in all word-positions, whereas children in the second group (variable substitute; VS) varied the substitute within and across word positions. The two groups of children were matched, as closely as possible, on variables for age, phonological knowledge, receptive vocabulary, the sound that was chosen for treatment, and its word-position (i.e. either word-initial or word-final position). Traditional treatment techniques were employed so that only the target sound was presented during therapy sessions. Results confirmed the hypothesis in that all children in the CS group learned the treated sound and generalized it to other contexts; by contrast, no child in the VS group evidenced knowledge of the treated sound by the conclusion of the experiment. These results provide further evidence of the importance of category representation for phonological learning and generalization.

Spectral analysis of target-appropriate /t/ and /k/ produced by phonologically disordered and normally articulating children

Previous research (Forrest, Weismer, Hodge, Dinnsen and Elbert, 1990) has shown that some phonologically disordered children differentially mark seemingly homophonous phonemes; however, the resulting contrast may be spectrally distinct from that produced by normally articulating children of the same age. In the present investigation possible sources for these differences between normally articulating and phonologically disordered childrens productions of target-appropriate phonemes were pursued. Spectral characteristics of seemingly correct productions of /t/ and /k/ in word-initial position were analysed for four normally articulating and seven phonologically disordered children to assess the effect of recency of acquisition, depth of knowledge of the contrast and/or the effect of a phonological disorder on accuracy and variability of production. Results revealed that children who had acquired the velar-alveolar contrast more recently, and who had incomplete knowledge of that contrast, produced target-appropriate /t/ and /k/ differently from their normally articulating peers and other phonologically disordered children with greater knowledge of the contrast. Further, the phonologically disordered children with incomplete knowledge of the velar-alveolar contrast were less variable than the other phonologically disordered or normally articulating children in the spectral characteristics across repeated productions. Analysis of the spectral characteristics of word-initial /t/ and /k/ at a later point in time indicated similarities between all speaker groups in the spectral parameters that distinguished the velar from the alveolar stop. However, the stability of these parameters across repeated productions decreased for the phonologically disordered children with greater knowledge of the contrast. These effects are related to motor skill development and found to be consistent with previously demonstrated patterns of skill acquisition.

A re-examination of phonological neutralization'

One of the most fundamental constructs of phonological theory past and present is ‘neutralization’, i.e. the merger of a contrast in certain contexts. It is as basic as such other constructs as ‘contrast’, ‘distinctive feature’, and ‘segment’. While there exists a substantial body of literature on the phonetics of various phonological constructs (e.g. acoustic correlates for features, acoustic invariance, descriptive phonetics of particular languages, instrumental measurement techniques and segmentation criteria), the phonetics of neutralization has largely been assumed on the basis of casual impressionistic phonetics. The assumption is that forms which are distinguishable phonetically and phonologically in certain contexts and/or levels of representation (e.g. intervocalic voiced and voiceless obstruents in German) are under certain other well-defined circumstances totally indistinguishable at the level of phonetics (e.g. only voiceless obstruents occur word-finally in German).

On Word-Initial Voicing : Converging Sources of Evidence in Phonologically Disordered Speech

The purpose of this study is to bring related sources of data, i.e., phonological and acoustic phonetic, to bear on the characterization of two childrens disordered phonological systems. Auditorily-based phonological analyses indicated that the children exhibited a superficially similar pattern of error involving the voice contrast in word-initial obstruent stops, even though both children accurately produced the voice contrast in post-vocalic stops. Acoustic phonetic analyses indicated, however, that one of the children systematically effected the voice distinction using closure duration and voice onset time, whereas the other child did not. Despite the similarity of their errors as assessed by auditorily-based phonological analyses, the children had very different productive knowledge of word-initial voicing in stops. These findings have implications for the clinical assessment and treatment of children with phonological disorders.

On the characterization of a chain shift in normal and delayed phonological acquisition

Several theoretical and descriptive challenges are presented by childrens phonological substitution errors which interact to yield the effect of a chain shift. Drawing on an archival study of the sound systems of five children (ages 3;5 to 4;0) with normal development and 47 children (ages 3;4 to 6;8) with phonological delay, one such chain shift, namely the replacement of target /theta/ by [f] and the replacement of /s/ by [theta], was identified in the speech of six children from the two subgroups. Different derivational and constraint-based accounts of the chain shift were formulated and evaluated against the facts of change and the childrens presumed perceptual abilities. An adequate account in either framework was found to require the postulation of underspecified and, in some instances, nonadult-like underlying representations. Such representations were able to reconcile within a single-lexicon model the presumed production/perception dilemma commonly associated with acquisition. Continuity was also preserved by limiting underlying change to just those lexical items which exhibited a change phonetically.

On the lawfulness of change in phonetic inventories

Changes in the phonetic inventories of 34 children (ages 3;4 to 6;8) with functional (nonorganic) speech disorders were analyzed in terms of distinctive feature oppositions. All subjects received conventional minimal pair contrast treatment to induce changes in their phonetic inventories. The changes were found to be governed by the same principles that govern cross-sectional variation before treatment. Sounds were added (or lost) consistent with implicational relationships among feature distinctions as set forth in Dinnsen, Chin, Elbert and Powell (1990).

Impact of substitution patterns on phonological learning by misarticulating children

Learning and generalization of treated sounds to different word positions is a desired outcome of intervention in the phonologically disordered childs system. Unfortunately, children do not always learn the sound that is treated; nor do they always demonstrate across-word generalization. One possible explanation for differences in treatment outcome may relate to the pretreatment substitution patterns used by different disordered children. This post-hoc analysis of treatment data examines the effects on sound learning and generalization of consistent versus inconsistent substitutes. With a consistent substitute across-word position (CS), the same phone was used in initial, medial and final position for a phoneme that was not in the childs inventory. An inconsistent substitute was evidenced by a different phone for a target sound in each position of a word (InAP), or even within word position (InWP) for an error sound. Fourteen children with severe phonological disorders were treated on an obstruent in in...