Problemas de altavoz con mi iPhone 12 Pro

Hello,

I’d like to ask for help please. My iPhone 12 Pro is new and has a 100% battery. However, for a few weeks now I’m experiencing a problem: when I’m charging my phone and listening to music, the sound crackles and cuts out. At first I thought it was a charger issue, but even without charging the phone, or with headphones, the sound crackles and stops on its own. In my headphones there are really unpleasant and worrying explosion-like crackling noises. I’m trying to search the internet for solutions to fix it. I first cleaned the speakers and blew them, then restarted my phone each time; the latest update is installed and my storage space is fine.
I’m thinking of seeing a repair shop to get information, but before that, if possible I’d like to know where the problem comes from and how to fix it. Thank you very much in advance for your responses and help.