A karaoke apparatus is provided in which a plurality of singers can sing at a time and superiority/inferiority of singing voices can be matched. One karaoke music piece is performed, and two persons sing the music piece at a time by using different microphones. Singing voice signals input through the...http://www.google.fr/patents/US6352432?utm_source=gb-gplus-shareBrevet US6352432 - Karaoke apparatus
