Duplex - Is it better to install carpet in 2nd floor Unit?

[Cindy Hughes]

Hi, we are pretty new to landlording and have a question about a duplex we purchased several months ago.  The 2nd floor tenants recently moved out and we are taking the opportunity to upgrade the electric in the apartment, and also freshen it up a bit.  The apartment has pretty nice hardwood floors throughout, minus the kitchen and bathroom (kitchen is vinyl, bathroom is tile).  It also has non-painted trim and baseboards!  Is it recommended to carpet the second floor of a duplex to try to lessen the noise?  The first floor is also all hardwood and it seems the sound travels pretty easily between the units.  

Would one or the other be a factor in what we ask for in rent?  In other words, is one more desirable than the other and is it worth the money to put carpeting in?

Thanks so much!!