Signal processing for an acoustic sensor bi-directional communication channel is presented herein. The acoustic sensor can comprise a micro-electro-mechanical system (MEMS) transducer configured to generate, based on an acoustic pressure, an audio output; and a bi-directional communication component configured to send and/or receive data that has been superimposed on the audio output using common mode signaling, time division multiplexing, or frequency separation. In an example, a signal processing component is configured to send the audio output directed to an external device utilizing differential mode signaling between respective pins of the acoustic sensor; and send the data utilizing the common mode signaling comprising a sum of voltages of the respective pins. In other examples, the signal processing component is configured to send and/or receive the data, and send the audio output, during different time periods; or send the data based on a frequency range outside an audio band.