SPSU professors present stadium horn research
Dr. Richard Ruhala, associate professor and program director of the Mechanical Engineering Department, and his wife, Dr. Laura Ruhala, also an associate professor in the Division of Engineering, traveled to San Diego, last week to present their research on vuvuzelas, the horns made popular by the 2010 World Cup, at the Acoustical Society of America (ASA) Conference.
The Ruhalas teamed up with researchers from Georgia Tech to study the effect of these loud horns on hearing and found that the sound levels at the player’s ears from single horns ranged from 90 to 105 decibels. The horn’s impact is greatest when blown simultaneously with many others, such as at the World Cup. This research documented that the levels within a stadium may well approach 120 decibels.
“For perspective, 100 decibels is the level of noise typically heard at a rock concert. An ambulance siren or pneumatic jack hammer produce about the same level of noise as the vuvuzelas in a stadium – 120 decibels – which is at the threshold of feeling [the sound] and produces a ticklish sensation in your ears,” said Dr. Richard Ruhala, who holds a doctorate in acoustics.
“The threshold of pain is 140 decibels. Sustained exposure to 120 decibels is 1,000 times the acoustic energy that causes hearing loss [with longterm exposure]. That’s why the Occupational Safety and Health Administration requires people working near those noise levels to wear hearing protection.”