A noise few people are aware of has one Invercargill man banging his head against the wall – literally.
Barry Munro claims low-frequency noise has been a problem for him since the first week of July, 2008.
Mr Munro said air-conditioning units, heat pumps, industrial machinery, and large ceiling fans could all give off low-frequency sound vibration.
Mr Munro said the sound was "physically stressful".
His brother, who lives in the same house, cannot hear it.
"Not everybody is aware of it," he said.
"There is no evidence why I can hear it and my brother can't."
The best way he could describe low-frequency noise, he said, was it sounded like a hum.
Mr Munro said the noise had given him headaches almost every day for two years, and he had not had a decent nights sleep since it began.
The noise was always there, he said, but sometimes its intensity increased.
"All-over brain-cap headaches. Sometimes they can be extremely unpleasant, sometimes a mild ache."
He is interested in finding more people who are sensitive to low-frequency noise in Invercargill.
Invercargill City Council environmental health officer Sudhir Kumar said the council this year had received only two low-frequency noise complaints, which were from opposite sides of the city.
He confirmed a complaint had been received from Mr Munro about noise near his Waikiwi home.
Inspections had been carried out in the area, but no low-frequency noise had been detected by council officers, Mr Kumar said.
He said the council felt it had fully investigated Mr Munro's complaint, and was satisfied the environmental noise in the area met the requirements of the Invercargill District Plan.
Low-frequency noise was usually below the normal audible limit of 20Hertz.
In most cases, low-frequency noise was very subjective, Mr Kumar said, and was not likely to breach noise limits in the Resource Management Act 1991, or the Invercargill District Plan.
- The Southland Times
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