Identification and description of homogeneous subgroups within a sample of misarticulating children

A motor speech assessment for children with severe speech disorders: reliability and validity evidence

PURPOSE

In this article, the authors report reliability and validity evidence for the Dynamic Evaluation of Motor Speech Skill (DEMSS), a new test that uses dynamic assessment to aid in the differential diagnosis of childhood apraxia of speech (CAS).

METHOD

Participants were 81 children between 36 and 79 months of age who were referred to the Mayo Clinic for diagnosis of speech sound disorders. Children were given the DEMSS and a standard speech and language test battery as part of routine evaluations. Subsequently, intrajudge, interjudge, and test-retest reliability were evaluated for a subset of participants. Construct validity was explored for all 81 participants through the use of agglomerative cluster analysis, sensitivity measures, and likelihood ratios.

RESULTS

The mean percentage of agreement for 171 judgments was 89% for test-retest reliability, 89% for intrajudge reliability, and 91% for interjudge reliability. Agglomerative hierarchical cluster analysis showed that total DEMSS scores largely differentiated clusters of children with CAS vs. mild CAS vs. other speech disorders. Positive and negative likelihood ratios and measures of sensitivity and specificity suggested that the DEMSS does not overdiagnose CAS but sometimes fails to identify children with CAS.

CONCLUSIONS

The value of the DEMSS in differential diagnosis of severe speech impairments was supported on the basis of evidence of reliability and validity.

Commentary on “Treatment Decisions for Children With Speech–Sound Disorders”: Revisiting the Past in EBP

Purpose

This commentary, written in response to Alan Kamhi’s paper, “Treatment Decisions for Children with Speech–Sound Disorders,” further considers the “what” or goal selection process of decision making with the aim of efficiency—getting the most change in the shortest time.

Method

My comments reflect a focus on the client values piece of the evidence-based practice (EBP) triad through validating treatment decisions for individual clients using generalization data. Such data are ideal for demonstrating change according to specific benchmarks and suggesting that treatment was responsible for this change. Consideration is also given to deficit profiles and their implications for long-term outcomes when validating the effects of treatment.

Conclusion

Although the abundance of evidence suggests that a variety of treatment approaches are effective for children with speech–sound disorders, less is known about which are most efficient as compared to one another or for which specific children. Practitioners, however, are embracing EBP when they select a treatment by matching the research evidence with a client’s profile, collect systematic data, and use those data to demonstrate that change is attributable to treatment.

Visual feedback in treatment of residual phonological disorders

The use of visual biofeedback in the treatment of individuals who have Residual Phonological Errors is discussed. This type of treatment was used with clients who had not improved through traditional auditory/production based treatments. Biofeedback is conceptualized as a cognitive treatment that requires the client's analysis of visual information. The information is used in developing correct productions of Residual Phonological Errors. The reported results indicate that visual feedback is a viable alternative treatment for those who have been unable to develop correct sound production through traditional methods.

Four new speech and prosody-voice measures for genetics research and other studies in developmental phonological disorders

Research in developmental phonological disorders, particularly emerging subgroup studies using behavioral and molecular genetics, requires qualitative and continuous measurement systems that meet a variety of substantive and psychometric assumptions. This paper reviews relevant issues underlying such needs and presents four measurement proposals developed expressly for causal-correlates research. The primary qualitative system is the Speech Disorders Classification System (SDCS), a 10-category nosology for dichotomous and hierarchical polychotomous classification of speech disorders from 2 years of age through adulthood. The three quantitative measures for segmental and suprasegmental analyses are (a) the Articulation Competence Index (ACI), an interval-level severity index that adjusts a subject's Percentage of Consonants Correct (PCC) score for the relative percentage of distortion errors; (b) Speech Profiles, a series of graphic-numeric displays that profile a subject's or group's severity-adjusted consonant and vowel-diphthong mastery and error patterns; and (c) the Prosody-Voice Profile, a graphic-numeric display that profiles a subject's or group's status on six suprasegmental domains divided into 31 types of inappropriate prosody-voice codes. All data for the four measures are derived from one sample of conversational speech, which obviates the limitations of citation-form testing; enables speech assessment as a qualitative, semi-continuous, and continuous trait over the life span; and provides a context for univariate and multivariate statistical analyses of phonetic, phonologic, prosodic, and language variables in multiage, multidialectal, and multicultural populations. Rationale, procedures, validity data, and examples of uses for each measure are presented.

Linguistic processing and performance in articulation-disordered subgroups of language-impaired children

The linguistic and dichotic listening performances of three groups of nine children were studied. The groups were divided as follows: (1) Language-disordered children whose articulatory errors were primarily omissions; (2) language-disordered children whose articulatory errors were primarily substitutions; (3) communicatively normal children. All subjects participated in articulation testing, imitative language tests, analysis of a spontaneous language sample, and a dichotic word task. The articulatory omission group differed significantly from the substitution group on the imitative language test but not on the developmental sentence analysis. All groups demonstrated a right ear advantage, suggesting left hemispheric processing of the dichotic stimuli. The results of the present study and prior research are discussed in terms of possible sources of variability.

Effects of time between stimuli on the relationship of speech-sound discrimination skills to consistency of correct production of [s] and [r]

In this study, the relationship between consistency of correct production of [s] and [r] and ability to discriminate between speech sounds separated by three different time intervals is examined. Thirty-six children representing first-grade normal and [s] and [r] defective speakers served as subjects. Each subject listened to tapes of pairs of vowel-consonant-consonant-vowel bisyllables under each of three conditions: (1) 0.25 sec between bisyllables; (2) 2.0 sec between bisyllables; and (3) 10.0 sec between the bisyllables in each pair. The subjects' task was to determine whether the bisyllables in each pair were the same or different. Results of the statistical analyses indicated that the relationships which emerged were a function of the specific error sounds and the time between the stimuli to be discriminated. The findings are related to previous investigations of speech-sound discrimination skills in articulatory defective children.