I've used very rough "impulse" recordings to do binaural placement for sounds--as well as pure abstract textures as Malte suggested--with very nice results. See soundfiles and descriptions below from Karosta Project (Latvia, 2002-3) http://karosta.edworks.net/
best, d.
binaural.tunnel.study.1 [w/max.borisov][OGG 2min00sec 1.67Mb] http://www.gracies.org/derek/audio/field.recordings.2/binaural.tunnel.study....
An excerpted acoustic study of an abandoned Soviet aircraft bunker. Max Borisov wears ear-mount binaural microphones, and I test the space with bricks and stones. Max and I found this technique very interesting, as it allows one person to literally "become" a human microphone, and the other to perform for that audience/recorder [many thanks to Aaron Ximm for inspiration in this and other matters]. A clever soul might use these acoustic signatures to place other sounds in the same space virtually...
Original Formanta EMS-01 Synthesizer improvisation [OGG 2min08sec 1.34Mb] http://www.gracies.org/derek/audio/formanta.original.edit.ogg
Formanta.Drone [Surface.Noise] [OGG 7min10sec 4.92Mb] http://www.gracies.org/derek/audio/formanta.drone.edit.ogg
The first is an excerpt of a live improvisation made on Maxim Borisov's Formanta EMS-01 synthesizer. This is a big, nasty Russian synth that is almost totally useless for melody, but has this amazing noise-driven Low Frequency Oscillator with an array of filters behind it. All sounds on the first track came only from this random sequencer, without laying a finger on the keys. The second track resulted from a digital cross-breeding with surface noise from an old Soviet marching record--instant texture and depth!