Table 2. Statistical parameters of vocal features.

	Vocal Feature	Minimum	Maximum	Median	Mean	Std. Dev.
Several measures of variation in fundamental frequency	Jitter(%)	0.0008	0.1000	0.0049	0.0062	0.0056
	Jitter(Abs)	0	0.0004	0	0.0000	0.0001
	Jitter:RAP	0.0003	0.0575	0.0022	0.0030	0.0031
	Jitter:PPQ5	0.0004	0.0696	0.0025	0.0033	0.0037
	Jitter:DDP	0.0010	0.1726	0.0067	0.0090	0.0094
Several measures of variation in amplitude	Shimmer	0.0031	0.2686	0.0275	0.0340	0.0258
	Shimmer(dB)	0.0260	2.1070	0.253	0.3110	0.2303
	Shimmer:APQ3	0.0016	0.1627	0.0137	0.0172	0.0132
	Shimmer:APQ5	0.0019	0.1670	0.0159	0.0201	0.0167
	Shimmer:APQ11	0.0025	0.2755	0.0227	0.0275	0.0200
	Shimmer:DDA	0.0048	0.488	0.0411	0.0515	0.0397
Two measures of ratio of noise to tonal components in the voice	Noise to Harmonics Ratio	0.0003	0.7483	0.0184	0.0321	0.0597
	Harmonics to Noise Ratio	1.6590	37.875	21.92	21.6795	4.2911
A nonlinear dynamical complexity measure	Recurrence period density entropy	0.1510	0.9661	0.5423	0.5415	0.1010
Signal fractal scaling exponent	Detrended fluctuation analysis	0.5140	0.8656	0.6436	0.6532	0.0709
A nonlinear measure of fundamental frequency variation	Pitch period entropy	0.0220	0.7317	0.2055	0.2196	0.0915