Table 4 Applied functionals in the ComParE feature set

Functionals applied to LLD / Δ LLD

Quartiles 1–3, three inter-quartile ranges

One percentile (≈min), 99th percentile (≈max)

Percentile range 1–99

Position of min / max, range (max–min)

Arithmetic mean^a, root quadratic mean

Contour centroid, flatness

Standard deviation, skewness, kurtosis

Rel. duration LLD is above 25 / 50 / 75 / 90% range

Rel. duration LLD is above 25 / 50 / 75 / 90 % range

Rel. duration LLD is rising

Rel. duration LLD has positive curvature

Gain of linear prediction (LP), LP coefficients 1–5

Mean, max, min, std. dev. of segment length^b

Functionals applied to LLD only

Mean value of peaks

Mean value of peaks—arithmetic mean

Mean / std.dev. of inter peak distances

Amplitude mean of peaks, of minima

Amplitude range of peaks

Mean / std.dev. of rising / falling slopes

Linear regression slope, offset, quadratic error

Quadratic regression a, b, offset, quadratic error

Percentage of non-zero frames^c