Abstract: A system and associated methods for processing three-dimensional audio information for surround or stereo applications include a microphone assembly having three substantially coincident microphone elements. The microphone elements include one bidirectional-pattern microphone and two unidirectional microphones. The unidirectional-pattern microphones may generally face front and rear directions and align substantially with a null plane of the bidirectional element. As such, the output signals of the three microphones may be processed by a decoder into multiple channels, including, for example: left (L), center (C), right (R), surround left (SL), surround center (SC), surround right (SR), and height (H). Accordingly, the system may be used, for example, to capture sounds in three dimensions using a compact, small form-factor, single integrated microphone.