The TARDIS alters speech and text until it can be understood by the Doctor and his companions, but what about their other senses? How far does this machine go toward making the context of these distant times and places less than completely alien? I was told a while ago about the French of old in some period drama, that they bathed once a year and just piled on more and more perfume to deal with the smell. I doubt the English smelt much better? But if Rennette did smell mostly of poop and caked 6 month old BO when the Doctor was falling in love with her and snogging teeth that had never been brushed... On the other side of the equation the frails of the 20th century and there abouts would need some serious protection from 51st century pheromones and the such like before they're addled into queuing for an orgy when they should be saving the day.