No sound

So this is a strange problem that started at least two months ago.

Randomly, in the morning, my phone won't have any sound (texting, calls,

alarm, nothing!). Which means that the alarm I set doesn't make any

noise. When I wake up and look at my phone, I can see that the alarm is

going off but there is no sound. I have to restart the phone to get

sound back. At Apple's suggestion, I reset the phone using iTunes so

that it downloaded a fresh copy of iOS. I did NOT restore my apps. I

started as if it was a new phone. I also thought maybe it was the

lightning cable but I've since switched over to wireless charging. Has

anyone else experienced this?