Digital MEMS microphones will include an audio MEMS transducer connected to an audio preamplifier and an ADC. The output of the ADC is a single bit digital signal and is made available for the user. These microphones require digital circuits in the application system to receive and process the output signal, but this digital output signal is not sensitive to external electrical noise. Digital MEMS microphones typically have five pins, with provisions for sharing clock and output data pins between two microphones in a stereo application. The most common format used in digital microphones is pulse density modulation (PDM), which allows for communication with only a clock and single data line. I²S outputs are another option that include an internal decimation filter, which allows for processing to be completed in the microphone itself. This means the microphone can connect directly to a digital signal processor (DSP) or microcontroller, eliminating the need for an ADC or codec in many applications.