Of cause, one of the main tasks of sounddesign is to create subconscious emotional conditions at the listener. For example the sounddesign of the movie >silence of the lambs<. May you remind of the scene in buffalo bills basement, where little Catherine is caught in a well. Skip Lievsay had taken down pitched screams of animals to frighten the listeners and to put them into a awkward position. In reality there can´t be screams of animals, and much less down pitched... An other god example is the scoring of someone´s dying - in much movies you can hear breaking glass (there´s a study in barbara flückigers dissertation >sounddesign - die virtuelle klangwelt des films<). So the sounddesigner can provoke an emotion (by using the conditioning of the listener) to support the tragedy of a scene. Now my question: What are your tricks to generate threateningly, tightly, cheerfully, sadly, intimately, ... emotions? thanks for answering once before...
Silence can be very uncomfortable especially because people expect movies to be 'filled out' with sound.
Drones work, more so if you can accent them in the right places - be it with a volume lift or some specificly timed modulation.
Panning stuff (often with the help of spatial fx) is very useful, more so in the 5.1 environment. Used this technique in a short i worked on where i took happy sounds (in this case ambient kids laughing/playing about) and swirled them around the room, swelling/morphing into noise at the climax - mentally unstable adult with a child-like brain was about to murder someone. Juxtaposition or contrasting sounds works sometimes
Silence is one of the most under-utilized tools in the sound designer's repertoire to manipulate the audience.
Absolutely love the subject you brought with this topic!
Two really simple things that I think do a huge difference is the sudden volume raising in a tense moment to increase the public reaction to the scene and slowing down noises and raise it's volume slowly to create expectations. As an example, If you have footsteps being heard, when they're approaching you discretely slow the time between one step and another and raise it's volume. Sometimes people won/t even notice you used this second technique but it's sure to raise the tension!
There's lots! Can't wait to read what people will answer :)
The blog Designing Sound has a very interesting article on the newest Nightmare on elm street movie. The blog interviewed the Sound team that put together the soundtrack for the film and they have some interesting things to say about heightening emotion. Here's a link for the interview: http://cssstudios.wordpress.com/2010/05/26/designing-sound-a-nightmare-on-elm-street/
Counter-point/contrast always get overlooked. That works on two possible levels as well; against the picture, or against the sound design on either side of the event.
Several people have already mentioned silence. I love elegant uses of silence. Most often the best uses are those that are used as counterpoint, because of the accent it provides on the absence of aural information.