Is shielding necessary on interconnects & speaker cables


I have a tube cd player and a intergrated tube amp. I am getting ready to buy speaker cables and interconnects. Do I need to buy shielded or unshielded cables. What are the pros and cons of each type.  Is there sonically any differences. I am leaning towards unshielded. Thanks
holman
@petware when you know you have a lot of induced noise. :)

Like if you are picking up a radio station, or motors or fluorescent lights.
Thanks Erik, 
i was just curious if certain components like dacs  or streamers or turntables warranted shielding or not as a rule or if it's just on a case by case situation. 
It depends on your situation. I made a 12’ unshielded RCA cable and I have no issues with noise. They sound great! They don’t run next to anything that would induce noise however. You might consider shielding if that weren’t the case.