A method comprising: processing received image data and/or received depth data to track an object moving in a monitored scene space; determining a bearing of the tracked moving object in the monitored scene space; adaptively filtering outputs from a plurality of spatially diverse microphones in dependence upon the bearing of the tracked moving object in the monitored scene space to produce a combined audio signal, wherein the combined audio signal has directional gain in a target direction; characterized in that the method further comprises: defining at least a first portion of the monitored scene space and a second portion of the monitored scene space separated by at least one computer-implemented virtual boundary; detecting movement of the tracked moving object from the first portion of the monitored scene space to the second portion of the monitored scene space across the at least one computer-implemented virtual boundary; and in dependence upon detecting movement of the tracked moving object from the first portion of the monitored scene space to the second portion of the monitored scene space across the at least one computer-implemented virtual boundary, changing the target direction from a first direction being one of one or more target directions associated with the first portion of the monitored scene space to a second direction being one of the one or more target directions associated with the second portion of the monitored scene space, wherein the second direction is different from the first direction. processing received image data and/or received depth data to track an object moving in a monitored scene space; determining a bearing of the tracked moving object in the monitored scene space; adaptively filtering outputs from a plurality of spatially diverse microphones in dependence upon the bearing of the tracked moving object in the monitored scene space to produce a combined audio signal, wherein the combined audio signal has directional gain in a target direction; characterized in that the method further comprises: defining at least a first portion of the monitored scene space and a second portion of the monitored scene space separated by at least one computer-implemented virtual boundary; detecting movement of the tracked moving object from the first portion of the monitored scene space to the second portion of the monitored scene space across the at least one computer-implemented virtual boundary; and in dependence upon detecting movement of the tracked moving object from the first portion of the monitored scene space to the second portion of the monitored scene space across the at least one computer-implemented virtual boundary, changing the target direction from a first direction being one of one or more target directions associated with the first portion of the monitored scene space to a second direction being one of the one or more target directions associated with the second portion of the monitored scene space, wherein the second direction is different from the first direction. defining at least a first portion of the monitored scene space and a second portion of the monitored scene space separated by at least one computer-implemented virtual boundary; detecting movement of the tracked moving object from the first portion of the monitored scene space to the second portion of the monitored scene space across the at least one computer-implemented virtual boundary; and in dependence upon detecting movement of the tracked moving object from the first portion of the monitored scene space to the second portion of the monitored scene space across the at least one computer-implemented virtual boundary, changing the target direction from a first direction being one of one or more target directions associated with the first portion of the monitored scene space to a second direction being one of the one or more target directions associated with the second portion of the monitored scene space, wherein the second direction is different from the first direction.