US Patent 7660428 Ceiling microphone assembly

An overhead microphone assembly using multiple unidirectional microphone elements. The microphone assembly is installed overhead, generally above all the desired sound sources and below the undesired sound sources. The signals from these multiple microphone elements are fed into a microphone steering processor which can mix and gate the signals to ensure the best signal/noise ratio. The steering processor may also track the sound source dynamically when such tracking (source locating) is desired. The resulting audio signal from the steering processor may be further processed, such as echo canceling, noise reduction and automatic gain control.