  We describe a number of experiments that demonstrate the usefulness of
prosodic information for a processing module which parses spoken utterances
with a feature-based grammar employing empty categories. We show that by
requiring certain prosodic properties from those positions in the input where
the presence of an empty category has to be hypothesized, a derivation can be
accomplished more efficiently. The approach has been implemented in the machine
translation project VERBMOBIL and results in a significant reduction of the
work-load for the parser.
