Dennis, you must forgive Doug for his empty headedness with regards to the use of the word eh.
He is making the mistake of using "eh", in place of the American word "huh".
Unlike "eh", "huh" can be used on its own as a basic acknowledgement to someone speaking to them.
Nowadays, "eh" and "huh" have been joined to create a bit of a ludacrist response to someone.
It goes like this, altogether now, huhhuhhuheh heh huh eh
This lil limeric is best used with several inflections denoting levels of excitement or bordom.
It's also ok to mumble this when alone, which denotes self satisfaction. It works very well also when you cant give a straight answer.
Here's a variation: huh, huh, huh, heh, heh heh, huh heh.
John