Part Throttle Resonance Sound
 

I'm just wondering if this is normal, and I'm being paranoid, or something that requires attention. Sometimes, when under light throttle I'll hear a weird resonance sound from the passenger side of the car. If I push a little deeper into the throttle, it goes away, but there seems to be a zone of throttle opening that results in it.

The sound is very hard to describe...if I didn't know better I'd say it's a honky, resonant intake, but it's the wrong side of the car. To my ears it also sounds like an idler pulley with a failing bearing. I'm just wondering if this is a "they all do that" scenario or something I need to have looked at.