My Laptop charger is making a NOISE noise!? COMFORT!?

So I someone a laptop an Acer one and i've had it for around 3 years. Now today the warhorse tablet at the top wherever you cork it in (the wan bit on the zenith of the actual charger where the silver bit is as well) is making a abnormal crackling noise once I go to put it in. I usually walk off my laptop charging each the time when I use it only its never made a crackling swish earlier. What could be wrong? I've taken out my charger very soon.