I have a basic laser gun set. These laser guns make different sounds and blink LEDs when you hit each other. I would like to inject a small arduino to keep track of some stats - how many times hit, etc. I have some basic electronics knowledge and have built some arduino projects in past.
Question: Is there a way to "monitor" the speaker or LED hard lines using arduino so when a certain action happens on these lines, I can do something in my arduino? Besides arduino, I would like to use the least additional hardware as possible. If possible, to make it robust, I would like to hook into the hardwires and not use a mic that can listen to sounds or another hardware that can detect the light of the LED as on. Also, hooking into the existing IC of the laser gun would be beyond my skillset (I opened it up and the IC has no written markings on it).
Please help me to get this fun project started.