Abstract: An apparatus for conveying to a listener a pseudo low frequency psycho-acoustic sensation (Pseudo-LFPS) of a sound signal, including: frequency unit capable of deriving from the sound signal high frequency signal and low frequency signal (LF signal) that extends over a low frequency range of interest. Harmonics generator coupled to the frequency generator and being capable of generating, for each fundamental frequency within the low frequency range of interest, a residue harmonic signal having a sequence of harmonics. The sequence of harmonics, generated with respect to each fundamental frequency contains a first group of harmonics that includes at least three consecutive harmonics from among a primary set of harmonics of the fundamental frequency. Loudness generator coupled to the harmonics generator and being capable of bringing the loudness of the residue harmonic signal to match the loudness of the low frequency signal.