The mobile telephone call is headed towards extinction, research suggests, amid a surge of people of all ages using email, video and social media instead of making a voice call.
Almost one in three respondents in a major UK survey claimed they had not made any standard voice calls on their handsets in the past week, suggesting a dramatic shift in the way members of "generation smartphone" communicate.
In 2012, four per cent of Britons said they had not used their mobile phones to make a call. By last year, a quarter said they were not making calls, while this year the figure was 31 per cent.
Smartphone addiction is on the rise, however, with email, video calls and social network usage surging.
Deloitte, the business advisory firm, estimates more than 15 million people are disrupting their sleep patterns by checking for messages in the middle of the night - and often replying.
The sixth annual Mobile Consumer Survey examining the mobile usage habits of more than 4,000 people shows addiction is rising.
More than 80 per cent of users said they have a smartphone and one in ten of them instinctively reach for their phone as soon as they wake up. A third reach for their phones within five minutes of waking, and more than half within a quarter of an hour.
The majority are checking texts and emails.
In 2014, 48 percent used email. This year that figure is 71 percent.
The study said: "Email's appeal lies in its universality: every smartphone includes an email app. The email format has changed little over the last few years, yet it remains a simple and useful way to send and receive communication quickly."
The research also reveals that smartphone usage is increasingly affecting social behaviour, with a third of 18-24 year-olds use their devices "always" or "very often" when meeting friends, shopping or watching television.
A third of that group also noted that their excessive use of smartphones had caused arguments with their partners.
Deloitte's research also found that, for the first time, smartphone ownership (81 per cent) has overtaken laptop use (76 per cent).
Paul Lee, head of technology, media and telecommunications research at Deloitte, said: "It is clear that we are reaching an age of 'peak smartphone'. Given the market saturation, in the next 12 months we expect smartphone penetration to rise modestly, perhaps by no more than two or four percentage points."