What do you consider acceptable noises from your neighbor?

I'm sitting in the Phoenix airport working. (Bret dropped me off way early this morning so we could drive in together)
There are two rows of nice leather chairs back to back.
There is a gentleman playing an obnoxious loud game on his iPad directly behind and one over from me.
I put up with it for about 20 minutes.
It is quite loud. It is really bothering me.

I'm thinking I could get up and move. But these are the nice seats with the outlets for my laptop and my phone.
I could put in my earphones but I know that I will have my earphones in for the next 4 hours on my flight and don't want to.

So I get up the courage and ask him if he would mind turning it down.
Boy - was he nasty back to me. Asking me if it was bothering me? Asking me if the people having conversations around me were bothering me? He went on and on.

So it got me thinking. What is appropriate noise in public?
I have nasal issues- I blow my nose several times a day. Is that appropriate? Does it bother the people around me?
I have phone conversations with people around me? Is that appropriate?
Sometimes I might even slighly badly sing along to a song when I have my earphones in.

What do you think? I'm curious.