newest strange sound

[BillH]

Now for my newest strange sound of the week. In a post this weekend, I sought help regarding a rhythmic grinding or rubbing sound coming from the front wheel of my 1999 C230K (48,000 mi) at low speeds. Joel was kind enough to suggest a wheel bearing problem. Now, in addition, I and my wife are hearing an occasional high pitched whine coming from the front of the car at speeds above 35-40 mph. The sound goes away when the brakes are applied or the speed drops. Also the sound starts at a lower pitch and goes higher, then holds. Are these noises related? Any ideas on what's the source of the high pitched (and loud!) whine? Thanks in advance for your help