Remember reading in Business & Commercial Aviation over 30 years ago that the flyover noise level of a Queenair at 5,000' was louder than a 707 at the same altitude..! Was loud enough on the inside as my deteriorating hearing is proof of after 3 years in the NSW Air Ambulance, many noise complaints with our back of the clock departures from Mascot, people complaining of "noisy military aircraft"!