The Perendale originated in New Zealand from crossing the Border Cheviot with the Romney breed. They are an open-faced, medium-framed breed that produces bright, lofty, long-stapled, medium-wool fleeces. Developed as an easy-care sheep, they are both hardy and highly adapted to marginal forage-producing areas.
It depends how badly the eardrum is ruptured. Mine ruptured a couple of years ago from a bad ear infection, and it took me at least 3 weeks to get the ringing out of my ear. Depends a bit of how good you protect the ear from pressure changes; usually between 2 - 4 weeks. If you really do have an ear problem, do NOT mess 'round.
If you think you have a perforated eardrum, see a doctor. A tear in the eardrum can allow bacteria and other things to get into the middle ear and inner ear. If that happens, an infection could develop that can cause more hearing loss. Most perforated eardrums heal in a few weeks.