The disclosure relates generally to microphone and vibration sensor assemblies (100) having a transducer (102), like a microelectromechanical systems (MEMS) device, and an electrical circuit (103) disposed in a housing (110) configured for integration with a host device. The electrical circuit includes a variable gain signal processing circuit (203) that processes an electrical signal from the transducer and a gain control circuit (204) that compensates for transducer sensitivity drift caused by variation in an environmental condition of the transducer, and electrical circuits therefor.