ALWAYS WEAR EAR PROTECTION,,I know that the sound of the mower sounds kool to us sometimes, But once you get Tinnutis it NEVER gos away. there is no CURE... in cass you might not know what Tinnutis, its also called RINGING IN THE EARS. I have it in my left ear and there is no cure for it, (Doc) say no cure for it at this time. things that could cause it,, loud mowers,loud train horns, loud backpack blowers,I also work at a carwash in the winter all 5 pumps running at the same time not a good thing. if you think a contsant ringing in your ear or ears would be kool :-(( then DON'T WEAR EAR PROTECTION CLARKE OWNER CLARKE'S TOTAL LAWN CARE..NO QUEIT NITES EVER!