Table 4.

Ten most frequent earliest available PSI signs for participants with Speech Motor Delay (SMD) and with No Motor Speech Disorder (No MSD).

System	Domain	PSI Sign No.	PSI Sign Description	Data Reduction		% of Participants Positive on Sign		Attributes
				Perceptual	Acoustic	SMD	No MSD	Precision	Stability	Spatial	Temporal
Speech	Vowels
		5	Increased Duration for Mid-Vowels and Diphthongs		X	56.0	25.0	X			X
		6	Reduced % Vowel Phoneme Target Consistency	X		65.0	32.4		X	X
		7	Reduced % Vowel Target Consistency	X		66.7	28.7		X	X
	Consonants
		8	Reduced % Correct Glides	X		52.0	31.7	X		X
		12	Decreased 1st Moment on/s/Initial Singletons		X	53.3	47.7		X	X
	Vowels & Consonants
		17	Increased Diacritic Modification Index Class: Duration %	X		54.0	24.3	X			X
		18	Increased % of Epenthesis Errors	X		60.0	33.1	X		X
Prosody	Rate
		21	Increased Average Syllable Duration (ms) (without pauses)		X	52.0	7.7	X			X
	Stress
		23	Increased % of Prosody-Voice Codes15/16 Excessive Equal codes of all Prosody-Voice Codes 15/16 (uncircled & circled)	X		52.3	11.1	X			X
Voice	Laryngeal Quality
		29	Decreased Harmonic-to-Noise Ratio (dB) for Vowels		X	52.0	16.5	X		__a	__a
			Totals	6	4			7	3	5	4
			Mean (SD)			56.3 (5.6)	25.8 (11.8)

Notes: PSI = Precision-Stability Index; ms = millisecond; dB = decibel.

^aIndeterminate.