Lie detector tests that analyse voice changes in telephone conversations are being used to catch benefit cheats. One local authority has saved more than £336,000 during a pilot scheme, according to a report published today.

The first local council to run a trial of the “voice risk analysis” found that more people were volunteering that their circumstances had changed and that they no longer needed benefits. Early results from Harrow Council in northwest London show that, of 998 people assessed using the technology, 119 – 12 per cent – were identified as “high risk”. In the first seven months of the £63,000 pilot scheme, 43 of these 119 were found to have been incorrectly paid benefit.

Anecdotal evidence also suggests that the lie detector test acts as a deterrent to would-be fraudsters. More than a quarter of claimants volunteered that their personal circumstances had altered and that they no longer required benefits – more than double the rate of voluntary admissions before the trial started last May.

The £336,711.39 saving was made up of £284,461.67 in housing benefit and £52,249.72 in council tax benefit, the two areas in which the technology was tested.

Only 5 per cent of people refused to use the technology when told by officials that Harrow was piloting the voice risk analysis system as part of an initiative by the Department for Work and Pensions.

Edinburgh, Durham and Birming-ham councils are now also testing the system, which is run by Capita, the private sector company that manages the congestion charge in London.

Paul Osborn, chief of strategy and business support at Harrow Council, said: “Although we still have to review the final results of the trial after a whole year, to make sure the savings have been made direct through this technology, these interim figures suggest that the pilot scheme has been very successful. As well as saving money on those potentially fraudulent cases, this technology enables us to make sure that the vast majority of law-abiding citizens who are entitled to help get their benefits quicker.”

Voice risk analysis is also used by the insurance industry to combat fraud.

The technology enables trained operators to identify suspect cases at the start of a claim by analysing changes in a caller’s voice. Changes are measured against the caller’s “normal” voice which is recorded at the start of a phone call when a series of basic questions are asked to ensure that nervousness and shyness do not trigger alterations in voice patterns.

The operators are trained in intelligent questioning and behavioural analysis, which allows them to assess the level of risk in the conversation. The voice risk analysis supports the operator’s judgment. The technology monitors changes in the voice – including the tone – and performs thousands of mathematical calculations, resulting in the identification of different categories of emotional content. Language, dialect, speech impediments and pauses are all taken into account so as not to influence the test.

Griselda Colvin, Harrow Council’s benefits manager, said that some callers withdrew their claim at this early stage of investigation. “Some people have willingly said, ‘OK, I’m not going through with it, I’m withdrawing my application’, and that’s what we’re looking for – those are the cases we’re looking to identify.”

The council said that a potentially fraudulent claim is not dismissed on the evidence of voice risk analysis alone. Such evidence is taken as an indication that the case may warrant further investigation by the council’s benefit fraud team.

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