Table 2.

Names of all the features, code source used for collecting them, and a short description^a.

Feature			Code source		Short description
Pitch
	MedianPitch b	Little et al [36]		Median principal frequency
	MeanPitch	Boersma and Weenink [33]		Mean principal frequency
	StdDevPitch	Little et al [36]		SD in principal frequency
Jitter
	MeanJitter	Little et al [36]		Perturbation in principal frequency (mean variation)
	MedianJitter	Little et al [36]		Perturbation in principal frequency (median variation)
	LocalJitter	Boersma and Weenink [33]		Average absolute difference between consecutive periods, divided by the average period
	LocalAbsoluteJitter	Boersma and Weenink [33]		Average absolute difference between consecutive periods measured in seconds
	RapJitter	Boersma and Weenink [33]		Average absolute difference between a period and the average of it and its two neighbors
	Ppq5Jitter	Boersma and Weenink [33]		5-point period perturbation quotient
	DdpJitter	Boersma and Weenink [33]		Difference of differences of periods of principal frequency
Shimmer
	MeanShimmer	Little et al [36]		Amplitude perturbation (using mean)
	MedianShimmer	Little et al [36]		Amplitude perturbation (using median)
	LocalShimmer	Boersma and Weenink [33]		Average absolute difference between amplitudes of consecutive period
	LocaldbShimmer	Boersma and Weenink [33]		Average absolute base-10 logarithm of the difference between amplitudes of consecutive period
	Apq3Shimmer	Boersma and Weenink [33]		3-point amplitude perturbation quotient
	Apq5Shimmer	Boersma and Weenink [33]		5-point amplitude perturbation quotient
	Apq11Shimmer	Boersma and Weenink [33]		11-point amplitude perturbation quotient
	DdaShimmer	Boersma and Weenink [33]		Shimmer calculated by difference in differences of amplitude
MFCCc
	MeanMFCC (0-12)	Little et al [36]		13 features of mean MFCC
	VariationMFCC (0-12)	Little et al [36]		13 features of mean variation of MFCC
	RelBandPower (0-3)	Tsanas et al [39]		4 features capturing relative band power in 4 spectrum ranges
HNR d			Boersma and Weenink [33]		Signal-to-noise ratio
RPDE e			Little et al [36]		Pitch estimation uncertainty
DFA f			Little et al [36]		Measure of stochastic self-similarity in turbulent noise
PPE g			Little et al [36]		Measure of inability of maintaining constant pitch

^aWe collected the features using the code or methodology described in the corresponding code-source entry.

^bThe correlated features were removed, and features in italicized text were used to build the models. Feature names are preceded by the loosely defined umbrella category they belong to.

^cMFCC: mel-frequency cepstral coefficient.

^dHNR: harmonic-to-noise ratio.

^eRPDE: recurrence period density entropy.

^fDFA: detrended fluctuation analysis.

^gPPE: pitch period entropy.