Figure 2.

Signal flow diagram of the full BCI algorithm. The acoustic signals from the four microphones (two left, two right) are processed using a DOA estimator and a binaural beamformer. Afterwards, either the right or the left channel (corresponding to the DOA) is selected and transformed to a multichannel electrodogram (“master pulse generator,” this can be done using any speech coding strategy). The resulting pulse pattern is duplicated and ITD or ILD information is applied on a pulse-by-pulse basis before being sent to the left and right research processor coils. BCI = bilateral cochlear implant; ILD = interaural level difference; ITD = interaural time difference; DOA = direction of arrival.