I see many, many claims that a bloodhound’s ears and skin folds help it in tracking scents, but I’m not finding anyone who has done testing on whether these actually help, or are just genetic tagalongs of the highly developed sense of smell.
The only testing I’ve seen was whether the dog is thrown off the scent trail by various movie methods on MythBusters.
Anyone seen any proof of the ear/skin folds myths? 
No proof, cite, or experiment here.
But it does sound plausible. Picture smoke filling an area and then blowing away. It’s common to see it appear to cling to surfaces. I think what we are seeing is a nice visualization of a layer of air close to surfaces that does not change fast. Making a kind of shroud against the ground surface seems like it should help gather more of the clinging gasses, the scents, there.
I have no answer to the actual question but from the number of bloodhounds I’ve seen with nasty ear infections and smelly skin problems I would think those smells would interfere with their tracking ability.