Whether it be the sound of a certain bike; the sound of your own; or the sound of anything at all. For me a couple of things stand out. When I hear a bike go down Point Cook road and I hear the rumble. Or if I'm riding down a slope, engine braking and I hear that sweet spot in the exhaust. A good down shift gets me hot and bothered. Especially from 4th to 3rd for some reason. What are your favourite sounds?