It’s become one of the plagues of modern society: the unwanted and unwelcome nuisance call. At one time they were 7pm sales cold calls for double glazing, then they evolved into overseas calls for time-share properties, and now they are usually automated recordings for insurance claims.

The problem is, when the phone rings, your automatic reflex is to answer it –and let’s face it, it has become rather unusual for your landline phone to ring these days so you want to answer it in case it’s a family emergency. Yet the reality is that the call is more likely to be an unwanted sales call than from someone you know.

The average person in the UK receives six nuisance calls a week, amounting to more than 7.8 billion a year, according to BT. The telco found that 74 per cent of its surveyed customers regard a nuisance call as the most annoying thing to happen to them, and 44 per cent find them so intrusive that receiving such calls physically raises their stress levels. The UK’s regulator Ofcom supported these findings when it found that 84 per cent of landline customers experienced nuisance calls.

In fact, 45 per cent of UK subscribers no longer answer their landline phone during the day in case it is a nuisance caller, and 24 per cent have resorted to unplugging their phone in order to get some respite.

No wonder that BT is today launching its most advanced call blocking phone to date. We at TelecomTV are rather dismissive about landline phones and the requirement to still have contracts in order to receive broadband services, but this is by far the most interesting development in the home phone market for some time.

BT rather unhelpfully claims it will stop “up to 100 per cent” of nuisance calls, which as any mathematician will tell you covers the entire spectrum of possibilities from 0 to 100. Heck, even a tub of lard could match those results. But annoying misuse of percentages aside, the phone does appear to be on the right track.

Its Call Guardian feature, based on “trueCall” technology, intercepts all calls from people not on your contact list. A recording asks unrecognised callers to announce their name prior to being connected, allowing you to accept or reject the call. Rejected numbers are then stored so they are blocked automatically if they call again.

The phone also has the ability to block withheld numbers and international numbers which account for a significant proportion of nuisance calls and users can also block by area code and mobile number. There’s an additional “Do Not Disturb” mode to give complete peace and quiet.

The BT8500 phone is now available for UK customers and I’ll be popping out to buy a couple. And if it doesn’t work as advertised, I’ll be making a few nuisance calls of my own.