Ipod classic 160 gb "Laser" noise when changing song

I just got my 7th generation, 160GB iPod Classic today, and I've noticed that while using it, it makes a light "purring" noise when I am going through the menus or changing the song. Is there something wrong with it? It sort of sounds like a computer hard drive winding down or working really hard. I feel like its going to explode or something! Does anyone have this or has seen this issue??? Thank you in advance!!