Efficient delivery of hierarchically structured meeting audio metadata with a bi-directional XML protocol

This paper explores user-centered metadata delivery through the example of hierarchically organized meeting audio metadata. Audio annotations that describe meeting scenarios can vary from low-level signal-based descriptors to high-level semantics. Users of meeting metadata also have widely varying requirements and hence want metadata at varying levels and detail. Thus, for efficient metadata access, it is vital to provide customization or choice of the metadata to be delivered using e.g. regions of interest and annotation detail specification. As well as proposing a user-centered metadata organization strategy, this paper introduces the use of a bi-directional XML protocol for metadata delivery. The combination provides advantages in terms of bandwidth efficiency when an example meeting metadata browser application is examined with practical user interfaces.