Extensions to the Speech Disorders Classification System (SDCS)

Abstract

This report describes three extensions to a classification system for paediatric speech sound disorders termed the Speech Disorders Classification System (SDCS). Part I describes a classification extension to the SDCS to differentiate motor speech disorders from speech delay and to differentiate among three sub-types of motor speech disorders. Part II describes the Madison Speech Assessment Protocol (MSAP), an ∼ 2-hour battery of 25 measures that includes 15 speech tests and tasks. Part III describes the Competence, Precision, and Stability Analytics (CPSA) framework, a current set of ∼ 90 perceptual- and acoustic-based indices of speech, prosody, and voice used to quantify and classify sub-types of Speech Sound Disorders (SSD). A companion paper provides reliability estimates for the perceptual and acoustic data reduction methods used in the SDCS. The agreement estimates in the companion paper support the reliability of SDCS methods and illustrate the complementary roles of perceptual and acoustic methods in diagnostic analyses of SSD of unknown origin. Examples of research using the extensions to the SDCS described in the present report include diagnostic findings for a sample of youth with motor speech disorders associated with galactosemia, and a test of the hypothesis of apraxia of speech in a group of children with autism spectrum disorders. All SDCS methods and reference databases running in the PEPPER (Programs to Examine Phonetic and Phonologic Evaluation Records) environment will be disseminated without cost when complete.

Figure 1

A framework for causality research in childhood speech sound disorders.

Figure 2

The Madison Speech Assessment Protocol (MSAP) speech sampling context hierarchy.

Figure 3

Sample display of the three windows viewable during acoustic analysis: the phonetic transcript window, the waveform window, and the acoustic analysis window. For acoustic analysis, the transcript window provides information on the coded utterances (displayed to the right of the numeric utterance), any Prosody-Voice Screening Profile (PVSP) codes used, the phoneme perceptually transcribed, and the phonemes marked for acoustic analysis (highlighted using a color code). The example displayed is the first coded utterance in a conversational sample. Data for the segmented utterance and all segmented phonemes can be viewed in the acoustic analysis window using a scrolling function to include views of onset and offset times for the utterance and each individual phoneme, pauses, characteristic F0, Mean F0, minimum and maximum F0, characteristic amplitude, and F1–F3. The moment data for a segmented fricative is displayed in the upper right corner of the acoustic analysis window. The electronic version of the figure allows enlarged views of these sample screens.