  Recent studies of hearing aid benefits indicate that head movement behavior
influences performance. To systematically assess these effects, movement
behavior must be measured in realistic communication conditions. For this, the
use of virtual audiovisual environments with animated characters as visual
stimuli has been proposed. It is unclear, however, how these animations
influence the head- and eye-movement behavior of subjects. Here, two listening
tasks were carried out with a group of 14 young normal hearing subjects to
investigate the influence of visual cues on head- and eye-movement behavior; on
combined localization and speech intelligibility task performance; as well as
on perceived speech intelligibility, perceived listening effort and the general
impression of the audiovisual environments. Animated characters with different
lip-syncing and gaze patterns were compared to an audio-only condition and to a
video of real persons. Results show that movement behavior, task performance,
and perception were all influenced by visual cues. The movement behavior of
young normal hearing listeners in animation conditions with lip-syncing was
similar to that in the video condition. These results in young normal hearing
listeners are a first step towards using the animated characters to assess the
influence of head movement behavior on hearing aid performance.
