At 20mph it was audible, at 40mph it was tolerable, but at 55 and above it was difficult to have a conversation. It sounded like my wife's SUV had the gnarliest knobbies known to man, when going down the highway, and all the noise from those tires was going straight into the cabin. I believe the primary cause of why this break/fix was needed stemmed from the service work she had done on the steering idler arm that was replaced the month before. We took that part to a tire shop that specializes in alignment, so after they replaced the part, the alignment was done at the same shop. They must have gotten heavy with the hammer when they replaced it, because we didn't notice this noise prior to that repair. I asked the mechanic who specializes in all makes of GM product if he thought we should replace both wheelhubs, and he said no. They are unrelated parts and just because one goes bad, doesn't guarantee the other will need to be replaced, so we only did the passenger side on the Bravada.