Acoustic and language analysis of speech for suicidal ideation among US veterans

Table 2 Summary statistics of significant features for suicidal and non-suicidal groups

Variables	Overall mean (std)	Non-suicidal mean (std)	Suicidal mean (std)	p-adj	ϵ²
Time between GCIs - mean	0.0039 (0.0009)	0.0038 (0.0009)	0.0043 (0.0011)	0.03	0.03
Time between GCIs - std	0.0072 (0.0028)	0.0074 (0.0029)	0.0060 (0.0019)	0.05	0.03
Energy contour for voiced segments - std	2.8089 (0.9230)	2.8806 (0.9270)	2.3614 (0.7624)	< 0.001	0.04
Energy contour for voiced segments - skewness	−0.6763 (0.3286)	−0.7059 (0.3288)	− 0.4916 (0.2613)	< 0.001	0.05
Energy contour for voiced segments - kurtosis	0.0866 (0.7950)	0.1583 (0.8101)	−0.3609 (0.5018)	< 0.001	0.06
Energy contour for voiced segments - average tilt of a linear estimation	−34.9081 (24.2386)	−36.2156 (24.4906)	−26.7487 (20.9610)	0.04	0.03
Energy contour for voiced segments - average MSE of a linear estimation	5.7945 (3.4302)	6.0285 (3.4929)	4.3348 (2.5833)	0.01	0.03
Delta energy entropy - std	0.3577 (0.0788)	0.3631 (0.0759)	0.3240 (0.0878)	0.04	0.03
Delta MFCC11 - std	0.1881 (0.0172)	0.1893 (0.0169)	0.1805 (0.0169)	< 0.001	0.04
Delta MFCC12 - std	0.1823 (0.0154)	0.1832 (0.0152)	0.1761 (0.0154)	0.01	0.03
Delta MFCC1 - std	1.0386 (0.2200)	1.0525 (0.2112)	0.9515 (0.2528)	0.05	0.03

Abbreviations: GCI Glottal closure instants, MSE Mean squared error, std. Standard deviation, MFCC Mel-Frequency Cepstral Coefficients, p-adj Adjusted p-value

ISSN: 1756-0381