The sound sets teeth on edge, makes skin crawl and sends a shiver down the spine. Just thinking about it gives some people the heebie-jeebies.
But what is it about the sound of fingernails scratching on a blackboard that elicits such a universal reaction?
Randolph Blake and two colleagues think they know — the sound's frequency level.
Their research has earned them an Ig Nobel, the annual award given at Harvard University by Annals of Improbable Research magazine for weird, whacky and sometimes worthless scientific research.
This year's winners honored — or maybe dishonored — at a raucous ceremony Thursday at Harvard's inappropriately opulent Sanders Theater include a doctor who put his finger on a cure for hiccups; two men who think there is something to the old adage that feet smell like cheese; and researchers who discovered that dung beetles won't tuck in to just any old pile of ... well, dung.
What started as a small event in 1991 to honor obscure and humorous scientific achievements has grown into an international happening, with some of this year's winners traveling from Australia, Kuwait and France. The awards are given out by real Nobel laureates, including Harvard physics professor Roy Glauber, who stays behind afterward to sweep up.
The nails on a blackboard research was part of a bigger, legitimate project, said Blake, a Vanderbilt University psychology professor who specializes in vision. He, along with Dr. D. Lynn Halpern and James Hillenbrand, did the research two decades ago while at Northwestern University.
Blake remembers some volunteers refusing to participate after learning they'd have to endure the obnoxious screeching.
Howard Stapleton's research into noise has more practical applications. He invented teenager repellant.
His device, called the Mosquito, emits a high frequency siren-like noise that is painful to the ears of teens and those in their early 20s, but inaudible to adults.
The invention grew out of his 15-year-old daughter's trip to the local store last year to buy milk. She came back empty-handed, having been intimidated by a group of teenage boys loitering outside the store.
Stapleton, who has sold and installed security systems for more than two decades, thought back to when he was 12 years old and he visited his father at work.
"I walked into this room with six people doing ultrasonic welding, and immediately ran right back out again the noise was so painful," Stapleton said. "I asked an adult, 'What's that noise.' And he said, 'What noise?'"
Stapleton's company, Compound Security Systems of Merthyr Tydfil, Wales, has sold hundreds of the units to retailers, local governments, police departments and homeowners all over the United Kingdom. The company is shipping its first Mosquito units for sale in the United States next week.
"The success of this has knocked my socks off," Stapleton said.
Dr. Francis Fesmire said he wasn't sure whether he was honored or embarrassed when he learned he'd won an Ig Nobel for his paper called — ahem — "Termination of Intractable Hiccups with Digital Rectal Massage."
"I'm a serious guy, and something I wrote in 1987 is coming back to haunt me," said Fesmire, an emergency physician and director of the emergency heart center at Erlanger Medical Center in Chattanooga, Tenn.
Fesmire, who stresses he is a real doctor who "someday wishes to be truly be remembered for my cardiac research," tried the technique for the first and last time nearly 20 years ago.
He knew that the technique could be used to slow a rapid heartbeat by stimulating the vagus nerve. The same nerve, when stimulated, can stop hiccups.
"I saw this patient who couldn't stop his hiccups, I tried these other maneuvers, and then I stuck my finger in his bottom," Fesmire said, emphasizing that it was the treatment of last resort. "Will I ever do it again? No!"
Dr. Ivan Schwab accepted his Ig Nobel for his work explaining why woodpeckers don't get headaches. Schwab, an opthamologist, said his writings are based on the research of deceased UCLA professor Phillip R.A. May, who received an Ig Nobel posthumously.
"I had heard about the Igs and this sounded like too much fun to pass up," said Schwab, who planned on dressing up as a woodpecker for the ceremony. "I'm very proud to be part of it."
