Composite Types and Function Parameters

Hi guys, got across an interesting problem of passing params to a function in postgre: is it possible to pass a composite parameter to a function without declaring a type first?

For example:

// declare a function
create function TEST ( object??? )
   ....
   object???.paramName    // using parameter
   ....

// calling
perform TEST( ROW(string, int, bool, etc...) )

Or do I have to do the type declaration for that parameter?

Thanks!