Psychoacoustic investigations have confirmed the known high correlation of auditory spaciousness and preference in concert-hall types of sound fields. Further, they have provided exploratory results which gave rise to the following interpretations: Auditory spaciousness is a multidimensional perceptual attribute, predominantly caused by early lateral reflections. Low-frequency reverberation may also contribute slightly, but is sensitive with respect to individual taste. All spectral components of early lateral reflections contribute to spaciousness. Spectral restriction of the reflections leads to less favorable judgments. Early lateral reflections which do not contain spectral components above about 3 kHz mainly create image expansion in the front-back direction, thus adding to the sense of envelopment of the listener. If components above about 3 kHz are present, image broadening is prominent. By means of a model of binaural signal processing which takes interaural arrival-time differences as well as interaural level differences into account, a quasiobjective measure of auditory spaciousness can be derived.