Pearl is almost always making some kind of noise. She is a Siamese mix so this is normal. When she jumps down from something or up towards something she'll make a little chirp noise. When she's running down the hall or just running in general she'll really make some very loud noises but it doesn't really sound like whirring or even meowing. It's more like singing to me. She'll go "Bobupbup". Her tail will also become fluffed up because she's so excited and happy.

My RB Sunny would also talk a lot and he would make the whirring noise that you're talking about. I sure do miss him. The rest of my gang don't seem to make noise when running but Ziggy will chatter when she sees something interesting outside.