There are a few possibilities for ear problems with this baby faced cat breed. Two which have been dismissed by supporters of the breed are that they might suffer from ear mites and deafness. I don’t know of any evidence which supports the view that the permanently folded down and forward ears cause ear mites. I would doubt that the prevalence of ear mites in Scottish Folds is any different to other cats and perhaps less because being purebred owners are more likely to take better care and keep them inside.
However, I’d expect cats of this breed to have very slightly poorer hearing than the average hearing standard of cats with normal ears. This is because the ear flaps obviously serve a purpose, namely to capture sound and channel it towards the ear canal leading to the eardrum. However, I would not expect the impairment to be anything other than slight and it would certainly not cause deafness in any degree.
The more interesting ear problem which might be suffered by the Scottish Fold is to do with body language. From the cat’s point of view, the folded ears are unable to communicate the ‘usual mood signals seen when a cat, becoming angry or scared, starts to flatten its ears for fighting’.
This backwards flattening of the ears of non-Scottish Folds transmits to other cats that they are in fight mode and that the other cat should take heed and beware. It is a method of preventing a fight and of protecting the ears from fight damage.
It is not clear if any Scottish Folds have encountered difficulties because their inability to employ this particular aspect of body language. There may be anecdotal evidence from some owners but I doubt it. It is more a hypothetical scenario rather than one which can serious concern owners of this cat.
There is nothing else to my knowledge that should concern guardians of this cat with respect to their folded ears. It is perhaps worth mentioning that the popularity of this ‘abnormal’ cat breed has waned a bit since its inception because nowadays people are more concerned about creating cat breeds from gene mutations which are deleterious to the cat’s health.