"Yes, it's irritating to listen to that constant, tuneless humming - and more than that, the humming is a sign of jangled nerves.
If you notice any of those telltale nervous habits in yourself - if you whistle through your teeth - juggle your keys - drum on the table - then it's time to start taking care of yourself.
Get enough sleep - fresh air - recreation - and watch your smoking. . . Remember, you can smoke as many Camels as you want. Their costlier tobaccos never jangle your nerves."