All about MEMS microphone from TDK Invensense. Link here (PDF)
A MEMS microphone IC is unique among InvenSense, Inc., products in that its input is an acoustic pressure wave. For this reason, some specifications included in the data sheets for these parts may not be familiar, or familiar specifications may be applied in unfamiliar ways. This application note explains the specifications and terms found in MEMS microphone data sheets so that the microphone can be appropriately designed into a system.
from Dangerous Prototypes http://ift.tt/2DtrXtk