HELP!!

hi im new to this but all i want is to know how to build an easy 2 way intercom, ive been lookin on the internet for ages but cant find any that i understand, coz i wanna know how it works and why.[/b]

here is what i found
http://www.electronic-projects.net/projects/intercom/index.shtml
also check electronicsforu.com, there are many types there.
hope you will find something interesting there.