1999 Chevy Suburban Left front wheel

You may have a loose //hanging wheel speed sensor or the brake pad is low enough to catch the metal sensor on the rotor, causing the noise, nevertheless, that wheel will have to come off to be able to inspect the area so we can determine exactly what it is, Im sure it nothing to be alarmed about

I didnt see where you stated putting new rotors on. What size suburban do you have? C2500, c1500, etc?

Yes, it is more than likely that the cv/ujoints have become pitted and are creating the noise you are describing, the only other possibility is the lockup mechanism inside the hub. And yes the wheel speed sensor is part of the hub.

This is either 2wd or a k1500. The c1500 is 2wd.

Not to nit-pick, but a 4wd you can get it up in the air and put it in drive to listen while the truck is stationary.
Have you tried spinning the wheel by hand when it is jacked up to see if it will make the noise? Any play in the wheel?

IF you have access to chassis ears, you may be able to narrow this down much quicker. Otherwise have someone outside the truck listen as you pass to see if this is somthing that can get narrowed down further regarding location.

Does this happen only when braking? IF you are slowing down and take your foot off the brake, is it still present?

If only when braking, can the pad move in the bracket or is it tight?