Table 3 Sixty-four low-level descriptors (LLD) of the ComParE feature set

Four energy-related LLD

Sum of auditory spectrum (loudness)

Sum of RASTA-style filtered auditory spectrum (modulation loudness)

RMS energy, zero-crossing rate

Fifty-five spectral LLD

RASTA-style auditory spectrum, bands 1–26 (0–8 kHz)

MFCC 1–14

Spectral energy 250–650 Hz, 1 k–4 kHz

Spectral roll off points 0.25, 0.50, 0.75, 0.90

Spectral flux, centroid, entropy, slope

Variance, skewness, kurtosis

Psychoacoustic sharpness and harmonicity

Six voicing-related LLD

F ₀ via sub harmonic summation (SHS) and Viterbi smoothing

Probability of voicing, logarithmic HNR by waveform matching

Jitter (local and delta), shimmer (local)