Elokuvateatterissa näkee nykyään kolmiulotteista kuvaa, mutta miksei siellä kuule kolmiulotteista ääntä? Vastaus on tietenkin, että kyllähän jo stereokaiuttimilla ja -miksauksella saadaan ääni liikkumaan vaikka millaisiin paikkoihin ja että monikanavasysteemeillä äänen sijoittelu eri paikkoihin helpottuu entisestään.
Mutta oikeastaan kolmiulotteisinkin ääni on yleensä aika litteää. Hollywoodin äänisuunnittelun historiaa ja nykytilaa tutkinut Benjamin Wright selittää:
In practice, mixers often avoid pin-pointed sound in 5.1 sound space because of its potential to distract audiences from the screen. Which is why many supervising sound editors and final mixers aim to fill the rear channels with rich but undefined backgrounds
There are some theoretical issues that still lurk in the shadow of 5.1. Mixers may want more channels capable of reproducing localized sound, but they must first overcome the conventional logic of surround sound mixing: avoid localized sound in the far left, far right, and rear. Tom Holman once quipped, “In Top Gun, when jets fly left to right across the screen and then exit screen right, what may be perceived aurally is the jet flying off screen as well, right into the exit sign.”
Toisin sanoen ääntä ei voi sijoittaa kovin paljon valkokankaan ulkopuolelle ilman, että äänilähde tuntuu olevan elokuvateatterissa eikä itse elokuvassa.
Saattaa olla, että kolmiulotteisesti esitetyissä elokuvissa pelivaraa on enemmän. Uuden Liisa Ihmemaassa -leffan re-recording mixer (jolle saisi ehdottaa fiksua käännöstä; Elävän kuvan sanasto ei tunne koko termia) Tom Johnson kertoo esimerkin:
We used the surround channels a lot to enhance the three dimensional world of Underland. We tried to give a sense of things coming off the screen by often putting them slightly (or often even more than slightly) into the surround speakers. We did this with the music and effects a lot, but also with the dialogue as well. For instance, at one point Alice tells the Caterpillar that she wouldn’t fight the Jabberwocky even if her life depended on it. He responds, ”It will!” We put that line in the Center speaker AND the center surround speaker to give it a bit of emphasis as his head comes out into the theater. This kind of treatment does not work at all in the 2D version of the film; it was really distracting and we found ourselves looking around the room because we were really aware of the surround speakers (especially when it was dialogue we were putting there). But when we ran the 3D version of the film, this technique really seemed to work pretty well.