Abstract: A portable apparatus including an acoustic signal generation device mainly comprises an input unit (IU) adapted to supply a digital input signal (in). The apparatus further comprises a delay line (DL) adapted to receive N samples of the digital input signal, to store and delay data values associated with the samples. The apparatus also comprises an arithmetic unit (AU) adapted to combine at least two delayed data values received from the delay line in order to them a modified data value, which is again loaded into the delay line and delayed by the value N, the modified data values together also forming an output signal (s), whose frequency content includes the fundamental frequency of the signal to be produced, enriched with harmonics of different intensities. The portable apparatus finally comprises an output unit (OU) adapted to produce a musical sound on the basis of said output signal.

Abstract: The present invention proposes a portable apparatus including an acoustic signal generation device. Such an apparatus mainly comprises an input unit (IU) adapted to supply a digital input signal (in). It comprises a delay line (DL) adapted to receive N samples of the digital input signal, to store and delay data values associated with the samples. It also comprises an arithmetic unit (AU) adapted to combine at least two delayed data values received from the delay line in order to form a modified data value, which is again loaded into the delay line and delayed by the value N, the modified data values together also forming an output signal (s), whose frequency content includes the fundamental frequency of the signal to be produced, enriched with harmonics of different intensities. The portable apparatus finally comprises an output unit (OU) adapted to produce a musical sound on the basis of said output signal, by converting it into an analog signal which sounds pleasantly to the user's ear.