Night time noise levels from a proposed wind farm near Lutterworth will damage residents' sleep patterns and disrupt their lives, it was claimed at an inquiry on Tuesday.

David Havergill, a member of the Institute of Acoustics (IOA), was speaking at the inquiry into whether an energy firm should be allowed to build an 11-turbine wind farm on land between Swinford and Walcote.

Energy firm Nuon UK applied for planning permission for the turbines last year, but then launched an appeal when Harborough District Council did not make a decision within the legal time limit.

Speaking on Tuesday, Mr Havergill said he was concerned as a resident of Swinford and as a member of the IOA, which is a professional body for people working in acoustics, noise and vibration.

According to the Stop the Swinford Wind Farm Action Group, which has campaigned against the proposals, some of the proposed wind turbines will be as near as 650 metres from Swinford.

Mr Havergill said: "With regard to separation of turbines and the effect they have on people's homes and lives, I have read professional reports which say the separation distances between turbines and people's homes should be 700 metres.

"This report came from Andrew Bullmore, who works in this field.

"He said the current figure of 350 metres distance should be revised because that figure was decided when turbines were smaller."

Andrew Newcombe, a barrister representing energy firm Nuon UK at the inquiry, said the firm had carried out its own surveys on noise from the site and the data showed they fell within legal limits.

However, Mr Havergill said he did not agree with the way the data had been applied.

Mr Newcombe said: "Assume for one second they [Nuon UK] are given planning permission which has a number of conditions on noise attached to it.

"If their data was wrong, and they weren't able to keep to the noise limits, then the experts Nuon got to carry out the research would be looking down the double barrel shotgun of a negligence action."

Despite this, Mr Havergill maintained that he disagreed with guidelines on noise used in the UK, because they allow noise levels to be higher at night because it is assumed people will be indoors.

The 12-day inquiry is due to finish tomorrow, after which inspector John Woolcock will send his recommendation to John Denham, Secretary of State for Communities and Local Government, for a final decision later in the year.