Table 3.

Speech classifications, Motor Speech classifications, and Dysarthria Subtype classifications in the Speech Disorders Classification System (SDCS). The five Speech classifications are mutually exclusive, as are the five Motor Speech classifications. The five subtypes of dysarthria classifications are not mutually exclusive. That is, a speaker can meet percentile criteria for more than one of the five listed dysarthria subtype classifications (i.e., mixed dysarthria).

Speech Disorders Classification System (SDCS)		Age (yrs;mos) at Assessment	Description	Reference a
Classes, Types, and Subtypes	Abbreviation
Five Speech Classification Types
Normal(ized) Speech Acquisition	NSA	3–80	Does not meet criteria for any of the four Speech Disorder classifications. Includes children 3-8 years old with only distortion errors	2, 3, 4
Speech Errors	SE	6–8;11	Age-inappropriate speech sound distortions	3, 4
Persistent Speech Errors	PSE	9–80	Age-inappropriate speech sound distortions that persist past 9 years of age	4, 5
Speech Delay	SD	3–8;11	Age-inappropriate speech sound deletions and/or substitutions	3, 4
Persistent Speech Delay	PSD	9–80	Age-inappropriate speech sound deletions and/or substitutions that persist past 9 years of age	3, 4, 5
Five Motor Speech Classification Types
No Motor Speech Disorder	No MSD	3–80	Does not meet criteria for any of the four Motor Speech Disorder classifications	2, 7
Motor Speech Disorder-Not Otherwise Specified	MSD-NOS	3–80	Meets Precision-Stability Index (PSI) criterion for MSD-NOS	2, 7
Motor Speech Disorder-Dysarthria	MSD-DYS	3–80	Meets Dysarthria Index (DI) and Dysarthria Subtype Indices (DSI) criteria for MSD-DYS	2, 7
Motor Speech Disorder-Childhood Apraxia of Speech	MSD-CAS	3–80	Meets Pause Marker (PM) criteria for MSD-CAS	6, 7
Motor Speech Disorder-Dysarthria & Childhood Apraxia of Speech	MSD-DYS & CAS	3–80	Meets SDCS criteria for MSD-DYS & MSD-CAS	2, 7
Five Dysarthria Subtypes
Ataxic		3–80	Cerebellar disorder	1, 2
Spastic		3–80	Upper motor neuron disorder	1, 2
Hyperkinetic		3–80	Basal ganglia disorder; increased movement	1, 2
Hypokinetic		3–80	Basal ganglia disorder; decreased movement	1, 2
Flaccid		3–80	Lower motor neuron disorder	1, 2

^a 1. Duffy (2013); 2. Mabie and Shriberg (2017); 3. Shriberg (1993); 4. Shriberg, Austin, Lewis, McSweeny, and Wilson (1997); 5. Shriberg et al. (2010a); 6. Shriberg, Strand, and Mabie (2017); 7. Tilkens et al. (2017).