Mixed-Delay Distributed Beamforming for Own-Speech Separation in Hearing Devices with Wireless Remote Microphones

In listening devices, such as hearing aids and augmented-reality headsets, it may be desirable to apply separate processing to the user’s own speech and to external sounds. In particular, listeners are most sensitive to processing delay for their own speech. If own-speech signals were processed along a dedicated low-delay pathway, then complex external sounds could be processed with more relaxed delay constraints. This approach is especially relevant to high-latency digital wireless systems, such as remote microphones and distributed sensor networks. The proposed mixed-delay beamforming system isolates the user’s own speech using a two-path structure resembling a sidelobe canceller. A fixed, causal beamformer is applied to the local microphones of the listening device. A second adaptive beamformer uses inputs from both local and remote microphones to separate external sounds. The proposed system is demonstrated using recordings of a group conversation with stationary and moving subjects.