THINK of a time when you’ve answered the phone and found you can’t hear who’s on the other end – what happens next?

Usually the caller will say some version of, “Can you hear me?”. That will prompt you to respond ‘yes’, which is exactly what a dangerous new scam is hoping for.

Criminals have been ringing people, asking them the question and then recording their response.

That simple little ‘yes’ is then used to sign people up for all manner of products and services they don’t want and probably haven’t even heard of.

The problem? Even if you insist to the company that you never agreed for their service, they will have that all-important recording of you saying ‘yes’.

This is known as a voice signature and it can be used to show you’ve agreed to buy something, whether we’re talking about a TV or a phone upgrade.

The worst case scenario is that they could threaten you with legal action if you don’t stump up payment.

Worryingly, the recording could even be used to give the go-ahead to credit card payments which have been flagged as suspicious.

The scam has been sweeping America lately, with the concern that it won’t take long to hit the UK.

CPR Call Blocker is a device which helps stop unwanted calls, and the people behind the company claim the scam is highly likely to hit Britain before long.

Kris Hicks of the firm told the Sunderland Echo: “Victims in the US have received a phone call from a familiar local area code and the other person on the other end of the line introduces themselves and their business.

“I know that people think it’s impolite to hang up, but it’s a good strategy. If you don’t recognise the number, don’t answer.”

There has also been a rise in fraudsters using fake helpline numbers to scam people into handing over their financial information.

In January consumers were warned that their personal information might be being sold to data companies too.