OK. It's time for you to get programming.
Try some of the examples in the Arduino IDE to get a feel for how a program goes together.
You are going to need to read from what you called the 'noise sensor' and when it exceeds a trigger level cause the LEDs to do something. What is this mysterious 'noise sensor' ? Do you have a link to it so that we can see what it is and what sort of signal that it is likely to output ?