- CNTV English - CCTV News

Why sound of fingernail scratching blackboard is disturbing?

11-07-2011 14:42 BJT

BEIJING, Nov. 7(Xinhuanet) -- Just imaging the scratchy and screechy sound made by fingernails running down a blackboard is annoying. Now scientists have found the reason why it has such effect.

The shape of inner ear is to blame -- human ear canals amplify the high pitches of the sound, making them disturbingly louder to ears, explained researchers from the University of Cologne in Germany reported by CBS.

The frequency of the annoying sound ranges between 2,000 Hz and 4,000 Hz, where human ears are most sensitive, suggested Michael Oehler, one of the researchers.

As the high-pitch parts of the noise in a record is erased, it sounds less unpleasant, noted the research.

The research also suggested that people's perception of sound also plays a role in how unpleasant it is.

Researchers asked two groups of participants to listen to the record of fingernails scratching blackboard. One group of listeners were told they were listening to horrible sounds, whereas the others were told they were listening to experimental music.

The participants who knew they were listening to noise reported higher level of unpleasantness than those who perceived they were listening to music.

These findings were presented last week at the annual meeting of the Acoustical Society of America in San Diego.

Editor:Wang Xiaomei |Source: Xinhua

Hot Videos view more

The celebrations are still continuing as the victorious coach, Joachim Loew, has been honored for his achievement in his hometown of Freiburg.
Germany coach Loew honored in hometown of Freiburg

Chinese men´s national team continued its preparations for next year´s Asian Cup, as they managed a one-all draw against visitors Jordan during a football friendly in Harbin, the capital city of Northeast China´s Heilongjiang Province.
China held to 1-1 draw by Jordan

The defending world champs came into the contest with a perfect 6-and-oh record, but they would be in for a tough first half before opening things up in the second.
USA beat Slovenia 119-76 in quarter-finals

Hot Stories more

UK authorities believe killer of James Foley is a British national

Across the UK the hunt is on for James Foley’s killer, who authorities believe is a British national. As Richard Bestic reports from London, Prime Minister David Cameron cut short his summer break to lead his government’s response.

Israeli war jets renews Gaza strike as truce talks stalled

Three Palestinians were killed and 40 others wounded in the intensive Israeli war jets´ airstrikes on the Gaza city on Tuesday night, shortly before an end of a 24-hour ceasefire in the Gaza Strip,

Missouri police arrest dozens after violent night

As the protests in the town of Ferguson, Missouri turned violent with police facing ´heavy gunfire´ from some ´criminal elements´, cops fired tear gas, stun grenades and arrested 31 demonstrators on Monday night.

Picture in news more

More Video News

Choose TV Program