Supervising sound editor/sound designer Dane Davis and his assistant Bill Dean created a whole new underground world for Bruce Hunt’s The Cave, an action-horror movie set in unexplored caves in Romania.Below the Line: What was your greatest sound-design challenge for The Cave?Dane Davis: The Creature. It’s virtually all human sounds, using some cutting-edge recording techniques. We extracted sounds that you wouldn’t ordinarily hear. It was very tricky. I had a feeling, even before I talked with the director Bruce Hunt, that the creature was de-evolved from other cave explorers, so it would be wrong to have him be animalistic. You had to believe it was coming from humans, even though they’re not physiologically very human anymore. We still wanted to evoke humans. Especially in the scenes where they confront each other, there’s mimicry going on. The creature vocalizations themselves are my 10 year-old son and me. I can do very high-pitched sounds. My son can do things even higher-pitched, which we could then slow down in radical ways. That was fun.BTL: I heard a lot going on in the surrounds. How did you use them?Davis: When we developed the sound, it seemed a very big part of the storytelling. You have humans, who can hear their enemies seeing them, since the creatures see with echo-location. What a great setup, in terms of the psychology of the sound design. We knew that the echo-location, all that clicking, had to be something these creatures could physically produce. We tried all kinds things. There are lots of little sounds: bat chirps and bone sounds, cartilage popping sounds, all things that this creature could do.One key technique was using sampling reverb, actually sampling real spaces. We used the Altiverb program. The human brain has an amazing ability to decode the shape and the size of a space. Most of us don’t realize that we’re doing it all the time, but that’s why using the sampled space of the Altiverb was so cool. You can tell when it’s accurate. We did experiments at our shop, where we recorded repeatable sounds, like clinking sounds, in a hallway that was very echoey. We sampled the space, did an impulse response into Altiverb, then ran the same dry sounds through the reverb in Pro Tools and compared the two. The similarity was scary. So we went to caves here in California and did scans. And we created some caves at Danetracks, just small caves, by stacking rocks and stuff. Once we got the impulse responses, I created these virtual spaces within Pro Tools sessions. That was the most complex Pro Tools sessions I’ve ever made—I’m famous for just grinding the system to a halt. There were several sampling reverbs running, but I’d also created hundreds of individual delays that could all be panned independently. We wanted believable spaces and key was to have enough variety for the different rooms. The same problem applied to the backgrounds. There were 80 or so different caves in the movie. We wanted them to sound different. We recorded thousands of drip sounds, all kinds of air-current sounds and built hundreds of variations. Bill [Dean] layered up all these things for the different rooms.Bill Dean: Taking elements of air and water and making them interesting room to room was pretty tough. Luckily Dane made over a thousand different variations of air and over two thousand different sections of drip. That way we could have some diversity and find something that would fit each of those cuts.Davis: We wanted to emphasize the degree of dryness of each space. Bill knew exactly how close each cave was to water [laughs]. As we got farther from any water, we wanted it to get drier, both to keep it from getting boring and as a dramatic device.BTL: Were you able to use any production sounds? Did you go to the Yucatan for any underwater sounds?Davis: That would have been fun, but underwater, things don’t sound like they look, so we had to create all of it. We did a lot of research and had planned to travel to some huge caves, but in the end, we got enough in the caves around California. There wasn’t any useable production sound. Everything recorded on set was a problem, because of the fiberglass, which had the wrong reflection characteristics.BTL: This was Bruce Hunt’s first movie as a director. What kind of challenges or freedoms did that bring?Davis: In a lot of ways he deferred to us. For creatures and things like that, we’d give him some examples. He’d say, “I like this and that” and then we’d go develop it further. He’s very into sound design and sound effects. In the final mix it’s always a battle between music and ambient effects. When we’re designing, we try to think about music and what it’s trying to do, but we have to make everything work as though there isn’t going to be music. The mix is especially tricky when defining space from one cave to another. Our quest was to make it sound different. It can only sound different if there is space in the music. So it’s a big challenge, especially in a movie like this where it’s so much about the space.BTL: What kind of creative input does your team have?Davis: I certainly encourage creative input. I work everybody to death, as I do myself, but I really want everybody’s ideas. With Bill, I would make all these sounds, then hand them to him and say, “Here Bill, make the 80 cave composites.”Dean: Then I’d start workin’ on it and say, “Hey Dane, I need some more less ploppy and more tinkly kinds of sounds.”Davis: It’s very interactive. Our whole shop runs that way. On this film it was a tiny crew. Julia Evershade cut explosions and stuff. Brian Watkins did all the big trucks and helicopters.BTL: You had a ton of machines, the rebreathers and bubbles. You must have had a tough time with it.Davis: The rebreathers were another trick because, unlike scuba, they don’t emit bubbles. All the breaths in and out had to be cut in between all the dialog, which was constantly changing. For the rebreathers, I had to develop some sound that was believable, like gas going in and out of these canisters. Even that sound was a cheat. I used Altiverb impulse responses, a tin can and rubber hose combined, and applied that to the dialog. We used that less than I would have liked, just for the clarity of the dialog, but I wanted the audience to believe that these guys were talking into a rubber hose.BTL: What part of your work on The Cave are you most proud of?Davis: When they’re talking over the com line and Strode gets the mole. It seemed to be arguing instead of growling. It couldn’t sound too mean or powerful, because then we would think it would just bite his arm off and run. It had to be a little bit playful because of his attitude, but it also had to be scary. That was a combination of really weird dog sounds.The scooters was another one. I wanted it to be like they were being pulled by these sort of scary things. I try to create different kinds of tension anywhere possible in the sound. Anytime we have two similar frequencies and they beat against each other, they make the audience uneasy, so we always try that. Something’s working really well and I’ll say, “Duplicate this and pitch it down a quarter tone,” like two not-very-good violinists trying to play in tune with each other. That works really well. Also the scooters had to pan completely 360. So I did the panning in Pro Tools to keep the movement locked to what we see. Bruce wanted the freedom and tonality of the movie to be as exaggerated as possible, so anything that we could move, we moved very precisely. The scooters were a great example of that, a very 3-D mix.
Written by Bob Bayless