Bike is a recent Specialized Sirrus Sport Disc with Nimbus 700x35 tires.

After 1,000 miles on the bike, I started getting a new sound from the front that I perceive as being the tire. It started going "fip fip fip" which increased or decreased with speed changes. It does this regardless of whether I'm braking, pedaling or coasting and is most noticeable above 10mph on a smooth road.

I cannot find anything stuck in the tread or on the tire. I cannot hear it when I lift the bike and spin the wheel. It's a new sound and my experience with machines and new sounds is that it never ends well.

I took it to the LBS where I bought it and after 2 weeks I got it back, but the sound was still there. Mechanic said he removed and sanded the disc brake pads as they were "glazed". He also did a full tune-up. Tomorrow it will go back but I sure hate being without a bike for another 2 weeks.

I live on an island with only 1 bike shop and fortunately it's a good one, and I'd really like to get rid of the sound. I'm willing to buy a new tire or a new set of tires (probably go with 700x32 this time) - I don't want to get stranded far from home on a back road.
Anybody else ever have a fip fip fip from their front tire?