Effectiveness of the feature perceptual bandwidth on the pairwise distinction of modes q1 and q4 from VAM . The perceptual bandwidth is closely related with the overall distribution of the spectrum. If spectral components of the emotional signal are dominant at high-frequency bands, the bandwidth tends to be at the lower frequencies because the noise floor is high as well. Otherwise, if the emotional signal has dominant lower-frequency components, then the noise floor tends to be lower and the bandwidth parameter probably takes a relatively greater value. Perceptual bandwidth behaves like sort of an adaptive noise floor threshold finder. Also shows that q4 and q1 are positively arousal modes. q4 which is in the negative valence domain owns a greater noise floor that yields a lower perceptual bandwidth with regard to q1 signal. As the perceptual bandwidth range of the q1 signal is mostly on the 6-7 kHz band where q4 signal is scattered on the 5-6 kHz band.