Sometime the end of this April 2013, billions of large flying insects called cicadas will make their appearance along with their characteristic stridorous noise. The male cicadas are the ones making this mating noise with "tymbal" soundmakers amplified by large resonance chambers found on body.
At 90 decibels, possible hearing damage may occur if a human ear is exposed to this level noise for more than 8 hours a day. At 120 decibels, less than 15 minutes of exposure can induce possible permanent hearing loss.
So... keep a pair of ear plugs in your purse or pants pocket and use them if the sound starts to get too loud.... or too irritating.
17 years in the making, this spring's cicada invasion generates early buzz. NBC News 4/10/13.