Do you hear your cellphone every time it rings? I don't. Depending on where I am in my home, it doesn't ring. I just suddenly hear the missed call tone. I don't care it around with me, if I go to the take a shower, take laundry to the basement, run out to my car, I am not going to hear my phone because it's sitting where I left it last.
When someone calls and doesn't leave a message or text, I don't call back. They can call me again if it's urgent. I just don't enjoy phone conversations. "What are you doing right now?" I'm talking to you on the phone. What are YOU doing?
And then I was asking why I text someone when I couldn't immediately respond to their response? I don't sit and wait. I might text and then go do something and only check for their response 30 minutes later. There is no reason to get indignant when someone doesn't text you right back. I bet you if I complained about a delay in his responses he'd get indignant as well.
Yeah, sometimes I don't hear it ring...