  Diarization of audio recordings from ad-hoc mobile devices using spatial
information is considered in this paper. A two-channel synchronous recording is
assumed for each mobile device, which is used to compute directional statistics
separately at each device in a frame-wise manner. The recordings across the
mobile devices are asynchronous, but a coarse synchronization is performed by
aligning the signals using acoustic events, or real-time clock. Direction
statistics computed for all the devices, are then modeled jointly using a
Dirichlet mixture model, and the posterior probability over the mixture
components is used to derive the diarization information. Experiments on real
life recordings using mobile phones show a diarization error rate of less than
14%.
