>overhearing my voice is not a violation of privacy //
But we're talking about recording your voice. Which I think is a violation of my privacy vs just listening to me passively - now that may not be enshrined in any law but then the law doesn't IMO [exclusively?] dictate what is moral.
I understand that making a recording of a phone call without notification is strictly disallowed in many states legislation? (eg http://en.wikipedia.org/wiki/Telephone_recording_laws#United...)