A method and system for removing noise due to bias electric power (MIC_Bias) or Time Division Multiple Access (TDMA) noise are provided. The system includes an interface with a microphone contact, for connecting to an accessory, an Analog-to-Digital (AD) converter for converting an analog voltage level, input via the microphone contact, into a digital voltage level, an audio processing unit for processing an audio signal input via the microphone contact, a switch for at least one of connecting and disconnecting the microphone contact and the AD converter, and a controller. The controller compares the digital voltage level with voltage levels stored in a look up table. The controller identifies a type of accessory connected to the interface. The controller also switches off the switch to prevent noise from being introduced into the audio signal via a wire connecting the microphone contact and the AD converter.