Without warning, the lights fade down inside Moscone West Convention Center, Room 2006. In the ensuing darkness, audience members are treated to a video montage from Silent Hill 4. Rendered in overexposed, grainy black and white, and set to alternately sad and creepy piano music, the video flashes a slew of barely intelligible, yet disturbing images.

When it comes to mood and ambience, Silent Hill series producer and sound director Akira Yamaoka clearly knows what he's doing.

In this week's GDC lecture "The Day and Night of Silent Hill" Yamaoka methodically explored a variety of topics, including the core components of horror, the relationship between sound and music, and the psychology of fear.

"I have written horror, Japanese style," Yamaoka reflected. And though he readily admits emulating American works by artists such as David Lynch and Stephen King, Yamaoka explained that the Silent Hill series is still "very rooted in the [Japanese] culture."

"Hollywood-style" horror, Yamaoka argued, tends to focus on shocking visuals and evil spirits, whereas Japanese-style horror relies on unseeable enemies, a sense of vengeance, and--perhaps most uniquely--a sad storyline. "It's not just a question of surprising someone, or showing shocking images," he remarked. In Japanese-style horror, Yamaoka explained, there is always a pervading sense of sadness, as if the story were "wet with tears."

Yamaoka did agree that "Silent Hill focuses very much on storyline," but pointed out that it has an "unclear" story that tends not to be "user-friendly." Yamaoka stressed the importance of this lack of narrative clarity, which not only forces players to "start developing a story themselves," but also "provokes a sense of fear." For instance, in Silent Hill 2, it turns out that the protagonist murdered his wife, though he pretends not to know. Consequently, there is a "destruction of identity" and a resulting unclearness that is deeply unsettling.

In a similar vein, Yamaoka identifies the feeling of uneasiness as a second core component of horror. Experiences that are uncomfortable or unfamiliar, he argued, lead to anxiety and fear. Yamaoka touted the use of fragmented information, commenting that "the creator doesn't need to explain everything." This attitude not only accounts for his heavy use of fog and mist, but also explains why no Silent Hill character is resolutely "bad." Instead, "every character has a multifaceted personality," because such unpredictability provokes fear.

"I think reality is a very important aspect of horror," Yamaoka continued. Nonetheless, he made sure to qualify that his working definition of "reality" is different than merely "looking natural," since people don't consciously notice all visual information conveyed to them. Thus, especially in light of the trend toward greater visual photo-realism, Yamaoka urged the need to work on "mechanisms to make the users feel like it's real." For example, in Silent Hill 3, one major design concern was taking advantage of the communicative power of eye movement. If a character's eyes aren't doing anything, Yamaoka pointed out, the interaction lacks a certain intangible something.

Shifting subjects to his expertise in sound production, Yamaoka remarked that he hardly separates general game production from sound production, advising, "You can't look only at sound or only at the game." He elaborated, "Silent Hill doesn't have what we normally know as music," warning that "music tends to be explanatory." For example, traditional soundtracks tend to imply when a scene is scary or romantic. The solution employed in Silent Hill, Yamaoka explained, was to abandon such conventions and use radio static--a sound to which players aren't instinctually attuned--to signify the presence of nearby enemies.

Toward the end of the program, Yamaoka stressed that Silent Hill isn't merely a puzzle-solving game, but rather an emerging form of interactive media in a more general sense. "What we call 'game' might change," he suggested.

Yamaoka was one of several Japanese speakers at GDC this week, as part of the "Focus on Japan" Global Developer Program initiative. Yamaoka's lecture, which he delivered in his native Japanese, was simultaneously translated into English and broadcast to attendees via special headphone sets.