1st October 2014,
By Camilla Turner, The Telegraph
The Royal Society publishes new research and warns of the danger that low-frequency sound emitted by wind turbines can pose.
Living near wind farms could lead to severe hearing damage or even deafness, according to a new research that warns of potential dangers from low-frequency sound. A study has found that the physical composition of the inner ear is changed “drastically” as a result of exposure to low-frequency noise emitted by wind turbines.
The investigation will be received positively by critics of the wind farms, who have long drawn attention to these harmful effects on the health of residents who live in the vicinity of wind farms.
According to today’s publication by the Royal Society in their new journal Open Science , the research was carried out by a team of scientists from the University of Munich .
It is based on a study of 21 healthy men and women between the ages of 18 and 28 years. After exposure to these low frequencies, scientists discovered changes in the type of sound emitted from the inner ear of 17 of the 21 participants.
The changes were found in the cochlea, the part of the ear that resembles a spiral-shaped cavity that is essential for both hearing and balance.
“We studied a very strange phenomenon in the human ear: the quiet sounds that a healthy human ear is constantly making,” said Dr. Marcus Drexl, one of the authors of the report.
“These sound like a very weak constant whistle that comes out of the ear as a by-product of hearing. We used this as a sign of how processes in the inner ear are changing. “
Dr. Drexl and his team measured these naturally emitted noises before and after the 90-second exposure through low-frequency noise.
“Usually the sound that the ear emits stays at the same frequency,” he said. “But the interesting thing was that these tones changed very drastically after exposure to low-frequency noise. “They slowly began to swing for a few minutes. This can be interpreted as a change in the mechanisms in the inner ear caused by low frequency sounds. This could be a first indication that the inner ear has been damaged. ” ” We don’t know what happens if you are exposed to this sound for long periods of time, (for example) if you live next to a wind turbine and hear it for months or years. ” Wind turbines emit a large number of the noise frequencies that correspond to the low frequencies used in the study, explains Dr. Drexl.
He said the study “could help explain some of the symptoms reported by people living near wind turbines, such as insomnia, hearing problems, and high blood pressure.” Dr. Drexl explained that the low frequency noise is not perceived as “intense or annoying” is simply because it is mostly inaudible to humans. “The lower the frequency, the less you will hear, and if it is even lower (editor’s note: in the infrasound range <16-20 Hz), you will not hear anything at all. ” People think if you can’t hear it, it’s not a problem. But it does get into your inner ear even if it doesn’t reach your consciousness. “
Sense of hearing – unheard of effect
Munich, October 1st, 2014
Cannot be heard, but still measurable: LMU neurobiologists show what low-frequency sound triggers in the human inner ear.
The deeper a tone, the more difficult it is for people to hear it. Nevertheless, the so-called low-frequency sound below 100 Hertz is perceived by the human inner ear and triggers the smallest mechanical reactions there, as LMU neurobiologists have now been able to show. They are currently reporting on their results in the journal Royal Society Open Science.
In high-tech societies, low-frequency sound occurs in many areas. For example, wind turbines, air conditioners, or heat pumps can cause these noises. The perception threshold is individually different. “The assumption that low tones are not processed by the ear because they cannot be heard or are difficult to hear is wrong. The ear reacts very well to very low-frequency sounds, ”says Dr. Markus Drexl from LMU. Together with colleagues led by Professor Benedikt Grothe, head of the neurobiology department at LMU, and from the University of Munich Hospital, he measured in a laboratory experiment how low-frequency sounds affect the inner ear.