Since Silent Hill 3, he worked in collaboration with Mary Elizabeth McGlynn and Joe Romersa for vocal compositions and performed live at several concerts. Yamaoka's sound commonly contains strong melancholy undertones and generally identifies with the dark ambient, industrial, trip-hop, and rock genres. Starting with Silent Hill 3, he played a more important role as the series' producer while also continuing with his music composition work. He is most well-known for his work for the Silent Hill series of video games, for which he composed all the music and sound effects in the whole series (excluding Play Novel: Silent Hill for the Game Boy Advance, 'Esperándote' in Silent Hill, composed by Rika Muranaka and both Silent Hill: Downpour and Silent Hill: Book of Memories, which were composed by Daniel Licht).