I hear everything while I am photographing, even composing... I don't know but I hear and even notice those around me (or at least I think I do).
Well yeah, I hear pretty much around me too, but even though I'm hearing it, I'm not really hearing it.
If one starts to talk to me I hear that too, I know what they're saying but it somehow doesn't arrive completely. But once I'm done doing my thing I am able to continue the conversation :P