Matthew Rockloff, left, and Nancy Greer give their acceptance speech after winning the Ig Nobel Economics Prize during ceremonies at Harvard University in Cambridge, Mass., Thursday, Sept. 14, 2017. The pair won for their experiments to see how contact with a live crocodile affects a person's willingness to gamble. (AP Photo/Michael Dwyer)

Scientists who discovered that old men really do have big ears, that playing the didgeridoo helps relieve sleep apnea and that handling crocodiles can influence gambling decisions are among this year's recipients of the Ig Nobel, the prize for absurd scientific achievement.

The 27th annual awards were announced Thursday at Harvard University. The ceremony featured a traditional barrage of paper airplanes, a world premiere opera and real Nobel laureates handing out the 10 prizes.

"It's a strange honor to have, but I am thrilled," Dr. James Heathcote told The Associated Press. A British physician, Heathcote won the Ig Nobel for anatomy for his big-ear research.

The awards are sponsored by the science humor magazine Annals of Improbable Research, the Harvard-Radcliffe Science Fiction Association and the Harvard-Radcliffe Society of Physics Students.

This year's winners—who each received $10 trillion cash prizes in virtually worthless Zimbabwean money—also included scientists who used fluid dynamics to determine whether cats are solid or liquid; researchers who tried to figure out why some people are disgusted by cheese; and psychologists who found that many identical twins cannot tell themselves apart in visual images.

Heathcote, whose study on ear size was published in the prestigious British Medical Journal in 1995, was inspired when he and several other general practitioners were discussing how they could do more research.

Marc-Antoine Fardin, left, accepts his Ig Nobel Physics Prize from Nobel laureate Eric Maskin during ceremonies at Harvard University in Cambridge, Mass., Thursday, Sept. 14, 2017. (AP Photo/Michael Dwyer)

When he asked why old men have such big ears, half his colleagues agreed with his observation; the others scoffed.

For his study, Heathcote measured the ear length of more than 200 patients and discovered not only that old men have big ears but that ears grow about 2 millimeters (0.08 inches) per decade after age 30. Women's ears grow with age, too, but their ears are smaller to start with, and men's big ears may be more noticeable because they tend to have less hair, he found.

"There's something magical about measuring the ears," he said.

Dr. Milo Puhan's Ig Nobel peace prize-winning discovery is a godsend for anyone who lives with an unbearably loud snorer. He found that playing the didgeridoo—that tubular Australian aboriginal instrument that emits a deep, rhythmic drone—helps relieve sleep apnea.

Puhan, director of the Institute for Epidemiology, Biostatistics and Prevention at the University of Zurich in Switzerland, studied didgeridoo playing after a patient with mild sleep apnea became convinced that it helped him.

Researchers from left, Alex Suarez, Christian Lo Cascio, Markus Heitz, Milo Puhan receive their Ig Nobel Peace Prize from Nobel laureate Oliver Hart during ceremonies at Harvard University in Cambridge, Mass., Thursday, Sept. 14, 2017. The team won for demonstrating that playing the didgeridoo is an effective treatment for snoring. (AP Photo/Michael Dwyer)

Puhan recruited volunteers who learned to play a roughly 4-foot-long (130 centimeter) plastic didgeridoo.

"Regular playing of a didgeridoo reduces daytime sleepiness and snoring in people with moderate obstructive sleep apnea syndrome and also improves the sleep quality of partners," his study concluded.

Why does it work? Puhan figures playing the didgeridoo helps people learn circular breathing (the technique of blowing out through the mouth while simultaneously inhaling through the nose) and strengthens the throat muscles used in breathing.

The economics prize went to a pair of Australians who found that if you want to limit your gambling losses, don't have a close encounter with a crocodile before hitting the casino.

Matthew Rockloff, head of the Population Research Laboratory at Central Queensland University in Bundaberg, and research assistant Nancy Greer, plunked a 1-meter (3-foot) saltwater crocodile—its mouth safely taped—into the arms of people about to gamble and watched what happened.

James Heathcote, left, reacts after receiving the Ig Nobel Anatomy Prize from Nobel laureate Eric Maskin (economics, 2007) during ceremonies at Harvard University in Cambridge, Mass., Thursday, Sept. 14, 2017. Heathcote won for his medical research study "Why Do Old Men Have Big Ears?" (AP Photo/Michael Dwyer)

The excitement caused by handling a dangerous reptile caused people with pre-existing problems to "gamble higher amounts, which over the long term will lead to greater gambling losses," Rockloff said in an email.

Like many projects that earn Ig Nobels, what seems silly on the surface can have a valid application.

"This was the first study to examine the emotional impact of excitement on gambling choices, which has obvious benefits toward addressing a very serious behavioral and mental health problem," he said.

Rockloff felt so fortunate when he learned of his Ig Nobel, he was tempted to press his own luck.

"I had to stop myself from trying to capitalize on that luck with a slot machine," he said.

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