Unraveling phonological conspiracies: A case study.

This paper focuses on three seemingly unrelated error patterns in the sound system of a child with a phonological delay, Child 218 (male, age 4 years 6 months) and ascribes those error patterns to a larger conspiracy to eliminate fricatives from the phonetic inventory. Employing Optimality Theory for its advantages in characterizing conspiracies, our analysis offers a unified account of the observed repairs. The contextual restrictions on those repairs are, moreover, attributed to early developmental prominence effects, which are independently manifested in another error pattern involving rhotic consonants.

The coronal fricative problem.

This paper examines a range of predicted versus attested error patterns involving coronal fricatives (e.g. [s, z, θ, ð]) as targets and repairs in the early sound systems of monolingual English-acquiring children.

On the anatomy of a chain shift.

Phonological chain shifts have been the focus of many theoretical, developmental, and clinical concerns. This paper considers an overlooked property of the problem by focusing on the typological properties of the widely attested 's > θ > f' chain shift involving the processes of Labialization and Dentalization in early phonological development. Findings are reported from a cross-sectional study of 234 children (ages 3 years; 0 months-7;9) with functional (nonorganic) phonological delays.

On the unity of children's phonological error patterns: distinguishing symptoms from the problem.

This article compares the claims of rule- and constraint-based accounts of three seemingly distinct error patterns, namely, Deaffrication, Consonant Harmony and Assibilation, in the sound system of a child with a phonological delay. It is argued that these error patterns are not separate problems, but rather are symptoms of a larger conspiracy to avoid word-initial coronal stops. The clinical implications of these findings are also considered.

On the interaction of velar fronting and labial harmony.

This article documents the typological occurrence and interactions of two seemingly independent error patterns, namely Velar Fronting and Labial Harmony, in a cross-sectional investigation of the sound systems of 235 children with phonological delays (ages 3;0 to 7;9). The results revealed that the occurrence of Labial Harmony depends on the occurrence of Velar Fronting, and that, when these processes co-occurred, all three predicted types of interactions were attested. A constrained version of Optimality Theory is put forward that offers a unified explanation for the implicational relationship between these error patterns and their observed interactions.

On the interaction of deaffrication and consonant harmony.

Error patterns in children's phonological development are often described as simplifying processes that can interact with one another with different consequences. Some interactions limit the applicability of an error pattern, and others extend it to more words. Theories predict that error patterns interact to their full potential.

The predictive power of optimality theory for phonological treatment.

The phonology and clinically induced learning patterns of a female child with a phonological delay (age 4;11) were examined from the analytical perspective of Optimality Theory. The analysis revealed that a Consonant Harmony error pattern affected alveolar stops from two different sources-from underlying lexical representations and from representations derived by an interacting error pattern of Deaffrication. The implications of that analysis for the selection of treatment targets were explored in a treatment study.

Comparative Markedness and Induced Opacity.

Results are reported from a descriptive and experimental study that was intended to evaluate comparative markedness (McCarthy 2002, 2003) as an amendment to optimality theory. Two children (aged 4;3 and 4;11) with strikingly similar, delayed phonologies presented with two independent, interacting error patterns of special interest, i.e.

Constraint conflict: the source of an unusual error pattern.

Certain phonological error patterns have been judged to be "unusual" or "idiosyncratic", posing a number of theoretical and clinical problems. This paper reconsiders an especially challenging case of an unusual error pattern documented by Leonard and Brown (1984). T (age 3;8) replaced all word-final consonants (except for labial stops) with [s] but more importantly inserted [s] after word-final vowels.

Typological predictions in developmental phonology.

Two common and seemingly independent error patterns, namely consonant harmony and gliding, are examined for their typological characteristics based on cross-sectional and longitudinal evidence from young children's developing phonologies. Data are drawn from the published literature and from the developmental phonology archives at Indiana University. An asymmetry is observed such that the occurrence of harmony is found to imply the occurrence of gliding, but not vice versa.

Implicationally Related Error Patterns and the Selection of Treatment Targets.

This paper compares some of the different claims that have been made concerning acquisition by traditional rule-based derivational theories and the more recent framework of optimality theory. Case studies of children with phonological delays are examined with special attention given to two seemingly independent error patterns, namely, place harmony and spirantization. Contrary to the expectations of derivational theories, these (and other) error patterns are argued to be implicationally related.

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

Several theoretical and descriptive challenges are presented by children's 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 children's presumed perceptual abilities.

Context-sensitive underspecification and the acquisition of phonemic contrasts.

Several competing proposals for the (under)specification of phonological representations are evaluated against the facts of phonemic acquisition. Longitudinal evidence relating to the emergence of a voice contrast in the well-documented study of Amahl (from age 2;2 to 3;11) is reconsidered. Neither contrastive specification nor context-free radical underspecification is capable of accounting for the facts.

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 children's 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.

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 children's 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 children's underlying representations and between children's underlying representations and their phonetic representations. With special emphasis on coalescence phenomena, it is suggested that the apparent diversity in children's cluster realizations can be reduced to four constraints on the form of underlying and phonetic representations.

Stimulability as a factor in the phonological generalization of misarticulating preschool children.

The relationship among six functionally misarticulating preschool children's phoneme-specific stimulability skills, the choice of treatment targets (i.e., stimulable or nonstimulable sounds), and generalization of correct sound production was explored in this prospective study.

Generalization to conversational speech.

Although changes in children's phonological systems due to treatment have been documented in single-word testing, changes in conversational speech are less well known. Single-word and conversation samples were analyzed for 10 phonologically disordered children, before and after treatment and 3 months later. Results suggest that for most of the children, there were system changes in both single words and in conversational speech.

Some constraints on functionally disordered phonologies: phonetic inventories and phonotactics.

The phonological systems of 40 functional misarticulators, ages 40 to 80 months were examined in terms of the nature and variation of phonetic inventories and phonotactic constraints. It was found that these properties of disordered systems were governed by severe constraints that yielded a typological characterization of such systems along with associated implicational laws. The principles governing disordered systems were also found to parallel closely the principles governing normal first language acquisition.

A functional analysis of phonological knowledge and generalization learning in misarticulating children.

It has been suggested that a child's productive phonological knowledge may be one factor that potentially accounts for individual differences in generalization learning observed among phonologically disordered children (Dinnsen & Elbert, 1984; Elbert, Dinnsen, & Powell, 1984). This paper evaluates the hypothesis that productive phonological knowledge influences generalization. Three related studies involving 6 functionally misarticulating children were conducted.

On the prediction of phonologic generalization learning patterns.

The purpose of this study was to obtain information on six children's misarticulation of consonant clusters in order to illustrate how certain factors influence generalization learning patterns. While all subjects evidenced generalization, individual differences in learning patterns did emerge. These patterns were explained in terms of the following three factors: (1) information about the children's unique knowledge about the phonologic system, (2) the linguistic relationships among sounds, and (3) the interaction of these factors with the treatment target.