how were you able to replicate the problem to them? Mine happens randomly
Are you able to hear the caller if you transfer to speaker, headset or some BT device?
I also had the same problem. Switching from speaker to headset sometimes fixed the issue. Very annoying. On my 3rd 4s and everything seems to finally be right on this one.
Maybe there is something wrong with the small earpiece speaker. Technically there are two speakers on the iPhone. The earpiece and the one at the bottom. Maybe the one at your ear is going out intermittently.
Hi, i am having the same issue as well. I am unable to hear anything unless i have my headphones plugged in or have it on speaker. Whenever I increase/decrease the volumn, it indicates that i have headphones in but i don't. If someone knows how to correct this issues please help me. Any advice would be greatly appreciated. Thanks.