Ear Speaker Not Working

I had this issue when the my iphone 13 was in warranty and I took it to apple service centre and they asked me to take backup as we might need to reset it and check it. But after two days it was automatically resolved. So, I didn’t bothered to take it again. Right after a month when warranty was over I faced the same issue. The ear speaker has crackling sound sometimes and sometimes it’s OK. Idk if that’s a software issue or a hardware. I also have updated my phone to latest ios version.