"Unlike standard propellers that turn at subsonic speeds, the outer 24–30 inches (61–76 cm) of the blades on the XF-84H's propeller traveled faster than the speed of sound even at idle thrust, producing a continuous visible sonic boom that radiated laterally from the propellers for hundreds of yards. The shock wave was actually powerful enough to knock a man down; an unfortunate crew chief who was inside a nearby C-47 was severely incapacitated during a 30-minute ground run. Coupled with the already considerable noise from the subsonic aspect of the propeller and the T40's dual turbine sections, the aircraft was notorious for inducing severe nausea and headaches among ground crews. In one report, a Republic engineer suffered a seizure after close range exposure to the shock waves emanating from a powered-up XF-84H."
Even if your aircraft doesn't come close to the speed of sound, the tips of the propellers will, leading to insane amounts of noise. The Russians, as they are prone to do, didn't care and did it anyways. https://en.wikipedia.org/wiki/Tupolev_Tu-95
https://en.wikipedia.org/wiki/Republic_XF-84H_Thunderscreech