London, June 15 (ANI): A British acoustic expert has opined that the conical shape of the popular Vuvuzela, which is making its presence felt at this year's FIFA World Cup in South Africa, is primarily responsible for its ear-splitting loudness.
Trevor Cox, president of the UK Institute of Acoustics and an acoustic engineer at the University of Salford, said: "The loudness can be explained by the bore shape, which is roughly conical, and flares."
"As well as creating sound at a frequency of 235 hertz, the instrument generates harmonics - sound at multiples of the fundamental frequency. We have measured strong harmonics at 470, 700, 940, 1171, 1400 and 1630 hertz. A flared instrument has louder higher-frequency harmonics than a cylindrical one," he adds.
"The flared instrument is perceived as louder because the higher harmonics are at frequencies where our hearing is most sensitive. This is partly why the conical saxophone sounds louder than the cylindrical clarinet," he said.
Since it produces 116 decibels at one metre, prolonged exposure to the Vuvuzela poses a risk to hearing, the Department of Communication Pathology at the University of Pretoria adds.
The Vuvuzela is like a straightened trumpet and is played by blowing a raspberry into the mouthpiece. The player's lips open and close about 235 times a second, sending puffs of air down the tube, which excite resonance of the air in the conical bore.
A single Vuvuzela played by a decent trumpeter is reminiscent of a hunting horn, but the sound is less pleasing when played by the average football fan, as the note is imperfect and fluctuates in frequency. It sounds more like an elephant trumpeting.
This happens because the player does not keep the airflow and motion of the lips consistent.ut that din sounds nothing like a trumpet or an elephant.
When hundreds of the Vuvuzelas are played together, you get the distinctive droning sound. The overall effect is rather like the sound of a swarm of insects.
Experiments on other noise sources show that louder sounds are more annoying.
The droning quality of the Vuvuzela makes it more annoying.
Broadcasters have to balance how much crowd sound to use compared to the commentators' voices.
If they make the crowd too quiet then the game lacks atmosphere, so they can't turn it off altogether. (ANI)