Can eustachian tube dysfunction eventually lead to permanent hearing loss?

ETD: It doesn't normally lead to permanent hearing loss, but if it is a long term problem that isn't treated and followed by an Otolaryngologist, it can lead to middle ear ossicular "bone" problems or a condition called cholesteatoma both of which can cause permanent damage to hearing. Fortunately, this can be treated and alleviated. See an ENT and get examined and a hearing test.