Canadian researchers who reported herring may use their flatulence to communicate were among the winners of this year's spoofs of the Nobel Prize.

The science humour magazine Annals of Improbable Research and groups at Harvard and Radcliffe universities award the Ig Nobels annually.

The 2004 Ig Nobels were handed out on Thursday at a ceremony at Harvard to "honour achievements that cannot or should not be reproduced."

Ben Wilson of the University of British Columbia, Lawrence Dill of Simon Fraser University in B.C., and their colleagues in Scotland, Denmark and Sweden won the biology award for their herring research.

The scientists said herring squeeze bubbles out of their swim bladders through an anal pore at night.

Herring tend to make noise more often when in the company of others, which suggests it plays a social role, the researchers wrote in the Royal Society's Biology Letter.

The Ig Nobel for physics went to Ramesh Balasubramaniam of the University of Ottawa, and Michael Turvey of the University of Connecticut and Yale University, for exploring and explaining the dynamics of hula-hooping.

Other winners included Jillian Clarke, a former high school student in Chicago who investigated the "5-second rule" that states if food falls on the floor and remains there for five seconds or less then it's fine to pick it up and polish it off.

Clarke sampled floors at the University of Illinois and found the surfaces were actually quite clean, but it doesn't take long for microbes to contaminate a morsel.

Jim Gundlach of the University of Alabama won the medicine prize for publishing a study showing a link between listening to country music and a higher rate of suicide.

The Coca-Cola Company of Great Britain won the chemistry Ig Nobel "for using advanced technology to convert liquid from the River Thames into Dasani, a transparent form of water, which for precautionary reasons has been made unavailable to consumers."

The company pulled 500,000 bottles of the water from the market last March after unacceptable levels of bromate were found.

Donald J. Smith and his father, the late Frank J. Smith, of Orlando, Fla., won the engineering prize for patenting the combover technique to cover up a bald spot with hair.