ENGINEERS are investigating complaints of continuous humming from a new sub-station built as part of the controversial £600 million Beauly to Denny power line.
Residents in the small rural community around Wester Balblair sub-station near Beauly claim they are being woken up at night by the noise, while being unable to sit outside during the day.
Tests are being carried out by developer Scottish and Southern Energy and Highland Council after reports of a recurring loud buzz a few weeks ago.
Residents believe it is linked to the expansion of the sub-station at the start of the 137-mile overhead power line which is being upgraded to 400,000 volts to carry renewable energy generated in the Highlands and Islands to the south.
The first section between Beauly and Fort Augustus went live two weeks ago.
A community leader recorded the noise being above acceptable levels early one morning.
Steve Byford, chairman of Kilmorack Community Council, has been woken up several times in the early hours at his home in Broallan, about a mile-and-a-half away from the site.
On one occasion, he registered 43 decibels using a downloaded app, whereas Department of the Environment guidelines suggest 30 decibels are an acceptable sound level in a bedroom at night.
He said: “It is very distracting and upsetting. The trouble is with the nice weather when you want to open the windows and let in the breeze at night, the noise has been so loud you are not able to do that.
Night shift worker Tara Ross, of Wester Balblair, described it as “horrendous”.
“It is driving us crazy. I went to bed the other morning and it was a nightmare. I got about half-an-hour’s sleep.
“You cannot sit outside in the garden on an evening. You are just zoned into the noise — you cannot block it out.”
Neighbour Cherry Ambrose said it was difficult to go back to sleep once she had noticed the noise.
She added: “I tend to switch on the TV so I can’t hear it,” she said. I find it easier to go back to sleep with the sound of murmuring voices.”
The noise was so loud last weekend it drowned out the sounds from the Belladrum music festival, according to community council vice chairman John Stewart who lives in Wester Balblair.
He said: “Sometimes you can pick up the words from Belladrum, if you know them, but Belladrum is just a one-off. This never goes away.”
Gavin Steel, a liaison manager with SSE, confirmed the organisation has received complaints from residents.
“We have arranged for a specialist consultant to carry out some noise monitoring,” he said. “They are in the process of analysing the data and we expect to receive early results very soon.”
He would not speculate on the cause of the noise until the results had been studied.
Highland Council has also sent officers to investigate.
The application to upgrade the line was greeted with huge opposition, mainly because the pylons are being replaced with much taller pylons. Objectors fearing the visual impact on the Scottish countryside wanted the line placed underground.