  When human listeners try to guess the spatial position of a speech source,
they are influenced by the speaker's production level, regardless of the
intensity level reaching their ears. Because the perception of distance is a
very difficult task, they rely on their own experience, which tells them that a
whispering talker is close to them, and that a shouting talker is far away.
This study aims to test if similar results could be obtained for prosodic
variations produced by a human speaker in an everyday life environment. It
consists in a localization task, during which blindfolded subjects had to
estimate the incoming voice direction, speaker orientation and distance of a
trained female speaker, who uttered single words, following instructions
concerning intensity and social-affect to be performed. This protocol was
implemented in two experiments. First, a complex pretext task was used in order
to distract the subjects from the strange behavior of the speaker. On the
contrary, during the second experiment, the subjects were fully aware of the
prosodic variations, which allowed them to adapt their perception. Results show
the importance of the pretext task, and suggest that the perception of the
speaker's orientation can be influenced by voice intensity.
