Phase represents the delay between an applied FORCE (electrical or mechanical) and the response to the applied force (electrical or mechanical). This is characterized as absolute phase or RELATIVE phase. Absolute phase is the intrinsic phase delay of the microphone and is independent of any external references. It represents the delay between the incident pressure and the OUTPUT electrical response. Relative phase is the delay between the output electrical response and the response of another microphone. Any relative phase measurement must be ESTABLISHED against a STANDARD. 

Phase represents the delay between an applied force (electrical or mechanical) and the response to the applied force (electrical or mechanical). This is characterized as absolute phase or relative phase. Absolute phase is the intrinsic phase delay of the microphone and is independent of any external references. It represents the delay between the incident pressure and the output electrical response. Relative phase is the delay between the output electrical response and the response of another microphone. Any relative phase measurement must be established against a standard.