I think it depends on how good your sense of smell is. Mine is really bad, so if I had my eyes covered and was wearing noise cancelling headphones, I wouldn’t be able to tell if there are people in my area unless they haven’t showered in a while… Being able to distinguish between people? I can’t even differentiate between the smells of popcorn and peanut butter.

On the other hand, I know someone who was able to smell a “coppery” smell on someone which no one else notice. Eventually she convinced him to see a doctor and they found a rare condition that I can’t remember which.