So I have a friend who went to Hestons restaurant where they had a seafood dish that was served with an Ipod that had sounds of the ocean playing on it.

A few things are bugging me about this.
1.How do you talk to the person opposite you? Do you just put one headphone in?
2.If so, then do you reckon Heston modified the headphones to accommodate this, so that there was just one headphone.

Anyway this brings me to my real question, do you think you can buy single in-ear headphones?