My speakers from my Macbook Pro 2012 are not working properly. Suddenly they have noises as a radio station which is not tuned on the way it supposed to. What can it be? I've already tried so many things I've seen on internet. I appreciate your help

Do you have the same issue when using headphones or external speakers? If not, then the internal speakers are bad and will need to be replaced. I find that the speakers in the older Retina models tend to deteriorate with age becoming weak & distorted.

What is the exact model of the laptop? You can get this information by clicking the Apple menu and selecting "About This Mac". We need the screen size and whether it is a "Retina" model.

The non-Retina model is now considered "Vintage" by Apple, but can still be repaired by an Apple Authorized Service Provider as long as the necessary parts are still available. I have rarely had to replace speakers on this model, so they may still be available. I'm not sure an Apple Store will perform a repair on a "Vintage" computer since they usually mail the laptop to an Apple repair depot as do some AASPs (at least this was the case for use a few years ago with one of our laptops).

If an official Apple repair is not available, then check to see whether an AASP can find somewhere else to purchase the speakers to perform the repair for you (most likely the speakers will be used, but fortunately I haven't seen problems with these particular speakers as they age). Unfortunately I don't recommend replacing the speakers yourself since everything in the laptop must be removed to access the speakers since they are located beneath the Logic Board and I/O Boards. It is tricky removing the Logic Board because the microphone & left speaker sometimes stick to the case, plus it is tricky reinstalling the Logic Board as well as reconnecting the internal LVDS display cable whose connector is very easily damaged even when being extremely careful as it is very short and goes at an awkward angle.

Try to check your MacBook Pro with Apple Diagnostics if it reports audio related error.

Use Apple Diagnostics to test your Mac - Apple Support

I haven't pulled that model apart to that extent in many years so I don't recall if there are any screens between the speaker and the opening, but it doesn't really matter...if the speakers are accidentally damaged, then they still need replaced. Due to how these speakers are installed, it is doubtful any foreign material is causing the distortion....older MBAirs on the other hand, this could be a possibility.

If you feel liquid may have gotten inside, then I would be more worried about that liquid damaging the Logic Board.

It is unlikely the problem will go away unless the speakers fail completely or the volume level is extremely low or muted.

The battery won't affect the speakers.