A microphone, cable with audio support, and a audio capable DVR is required for this. The systems that will be discussed in this transcript are capable of recording audio as well as broadcasting live audio over speakers. Security Cameras with Audio have built-in microphones that allow easy recording of audio from the camera to the DVR recorder. The built-in mic is usually sensitive enough to hear sounds from up to 40ft away in a quiet room. Although results vary based on ambient noise, these Security Cameras with Microphones below are a great way to record both video and audio.