The camera have a built in ultrasonic rangefinder. The frequency of the sound is a function of the distance to the car. You can use it as a burglar alarms so when the car is moved the frequency of the clicking sound will change. Nice feature, don´t you think ;).
Just kidding! Yes, sort of annoying sound. I really need to know more about the camera, but here are some things that you can test. How did you connect the camera. Using a template, onvif or custom url? It probably have something to do with how the sound in the camera is encoded and the codec in NCS. In the configuration of the camera can you change how it is encoded. Sometimes it is possible to change between AAC, g.711 and g.726. Test if that is possible. Also if it is possible to connect the camera to NCS using a different method than you use now. Is it the same problem with all cameras or is it with a specific one?
This is what I have for the moment.