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.
Weeks to Months: The perforation may heal in a few weeks, or may take up to a few months.Some perforations require intervention. This may take the form of a paper patch to promote healing (a simple procedure by an ear, nose and throat specialist), or surgery.