Table 4.

The LLD Features used in INTERSPEECH 2009 emotion challenge [37].

LLD(16 × 2)	Functionals (12)
(delta) ZCR	Mean
(delta) RMS	Energy standard deviation
(delta) F0	Kurtosis, skewness
(delta) HNR	Extremes: value, rel. position, range
(delta) MFCC 1–12	Linear regression: offset, slope, MSE