The interior cabin of a vehicle is provided with a vehicular sound-processing system that comprises an interior rearview mirror assembly, the mirror assembly including a mirror housing and a reflective element. An accessory is located in the interior cabin. The interior rearview mirror assembly comprises a user-interaction site for a wireless communication system, the wireless communication system communicating with the accessory. The user-interaction site comprises at least one microphone for producing an audio output in response to detection of vocal input of a human speaker in the interior cabin with the vehicle cabin noise superimposed thereon. Preferably, the user-interaction site further comprises at least one manually operated control input. The restricted-range wireless communication system preferably comprises one of a radio frequency restricted-range wireless communication system and an infrared restricted-range wireless communication system. Signals indicative of the vocal input detected at the user-interaction site of the interior mirror assembly are wirelessly broadcast to the accessory located in the interior cabin of the vehicle.