u/Haunting-Decision768

Hi. These are used headphones that worked for about a year and a half good.
Short time ago i noticed that the left ear cup is not as good at noise canceling as it was. Testing it in a total quiet environment i can hear that the in the NC mode that there is some continuous sound coming from it. Like a white noise or very light wind.
Is it fixable?
In normal mode they are playing really clear without any interference.