A:Answer The cameras in this kit do not have a microphone and use a speaker for the alarm. The NVR has 4 RCA Audio Input ports and 1 RCA Audio Output port. Audio should be a setting in the software for the camara that may be selectable if a mic is connected to the port. You can purchase a mic designed for CCTV at a low cost and run a new cable, or if the camera or the system is not yet installed, you can purchase a 3 way cable which has a Video line, Power line and an Audio line, you may also need to purchase a power line splitter which allows you to power both the camera and the mic from the one power line at the camara end of the cable run. Or a 4 or 5 way combo cable. Of course the more ways, the higher the cost.