Stevie Davies, 30, cancels three times before we get to speak. Although we have scheduled an interview, she can’t work up the courage to pick up the phone. She can’t remember a specific time when her fear of phone calls began; she just knows that, whenever she makes one, her mind goes blank and, she says, she becomes a “blithering wreck”.

Having suffered from anxiety and depression since she was a teenager, she sometimes needs to seek advice, and here her aversion to phone calls becomes problematic. At her lowest moments, she ends up having panic attacks, which she feels could be avoided if she had somebody to speak to. “I feel absolutely terrible after letting it get that far, and it normally takes me a few days to get back to normal,” she says via email.

About a year ago, Davies found a confidential textline she could message when feeling down. She has used it at work and in her car at the side of the road. She says she has found it more helpful than any medication or counselling. Crucially, it has allowed her to manage her anxious thoughts before she reaches breaking point.

We would never ask them to speak on the phone just because it’s easier for us. We need to do what’s best for them

Davies is far from the only person with an aversion to phone calls. Only 15% of 16- to 24-year-olds now view them as the most important means of communication, while a quarter of smartphone owners use their devices to make calls less than once a week. In the US, the average monthly number of texts sent on mobile phones exceeded the average number of calls as long ago as 2007. Many people, particularly young people, report discomfort and anxiety about answering the phone. What was once a vital form of communication has become, for them, an intrusion.

Where does this leave helplines? These have been an important part of the social fabric for more than 60 years; in Britain, the world’s first 24/7 helpline was born in 1953, when a vicar, the Rev Edward Chad Varah, founded the Samaritans. The service was prompted by a funeral he had conducted for a girl in her early teens, who had killed herself after becoming convinced she had a sexually transmitted disease. She was, in fact, just menstruating. “Here was a life that could have been saved if only there had been an intelligent person she could bring herself to talk to,” Varah said in a 1959 interview. So he set up an emergency phone line, where people who were lonely and despairing might “get some love from a stranger”. Calls were soon coming in at the rate of 100 a day.

Samaritans is now contacted more than 5 million times a year, in phone calls, texts, emails and face-to-face chats. Phone calls still account for about 4 million of those interactions, a figure that could fall when it offers more web-based services, which it plans to do by the end of next year. But this raises the question: is speaking on the phone better for people in despair than texting or emailing? Is something lost when we move from talking to writing?

‘Most of Childline’s highest-risk cases now come through webchat.’ Photograph: Georgiy Datsenko/Alamy Stock Photo

Jenni McCartney, who has volunteered for the Samaritans helpline for 35 years and chairs its board, currently answers some of its emails. “I think it’s the same quality of conversation, just written down,” she says. “You’re still a human on the other end of the line.” Samaritans recently commissioned research into the effectiveness of its email line. It concluded that email support was seen as meaningful and positive for most people, but there were some teething troubles. Volunteers talked about finding it hard to convey empathy in writing, or to match the verbal cues that were readily available on the phone. “I wish there was some way [we could convey] ‘Uh-huh’ or ‘Mmm’ or ‘Wow’ or whatever – just a kind of ‘Tell me more’ kind of noise,” said one.

Samaritans has been offering emotional support via email since 1994, but it still doesn’t have a web-based chat service or readily available textline. There is clearly a demand for such a service. The organisation that Davies uses doesn’t publicise its textline because it does not have the capacity to manage any increase in callers.

Childline, whose typical user is much younger than those contacting Samaritans, is embracing this tech revolution: contacts increased by 44% after it brought in online counselling in 2009, and 73% of its counselling sessions took place online last year. “It’s how children want to talk to us,” says Pauline Brennan, a helpline supervisor. “They don’t pick up the telephone to talk to each other any more, so we have to meet them where they’re at,” she says.

Walking around Childline’s London office, you can see how that has changed things. In a busy room, a few dozen volunteers sit in cubicles with computers in front of them. Many are typing hurriedly. Supervisors look over shoulders as anxious volunteers raise their hands to indicate concern about a webchat. Even in the middle of the day, the web and phone lines are at maximum capacity.

London service manager Wendy Robinson started volunteering as an adviser for Childline in 1990. “I was in a pop band!” she says. When she realised the impact she could make through counselling, she gave up her music career and trained to work as a children’s therapist. When she started, children were traipsing out to phone boxes in the dead of night to call Childline, away from family members who might hear them.

Children spend most of their time either at home, or at school – two places where it’s very difficult to make a private phone call. The web service has changed that. Today, children can contact Childline from school toilet cubicles, or huddled up in their bedrooms while abusive parents remain unaware. “There’s more privacy when you’re texting,” says Robinson. “I think that’s opened us up.”

Kate Cook, who was a founding member of Trafford Rape Crisis, points out that the initial draw for helplines was that speaking on the phone was more anonymous than written correspondence: “Even with a letter you’d have to disclose your identity [if you wanted a reply].” So Cook welcomes the rise of textlines. “The more ways you can be contacted, the more likely you are to overcome someone’s inhibitions about seeking help. That’s what these services are really supposed to be about, isn’t it?”

There are, however, challenges with building a rapport by text, where the caller doesn’t know that someone will respond straight away, let alone whether they can open up to them. “We don’t have our voice on webchat,” Brennan points out. “If you listen to mine, I come from Northern Ireland and it’s a soft voice. That’s helpful for children, but online I can’t bring in warmth, tone, pace, anything like that.”

And there is no context on a webchat. You can’t hear the sound of a train thundering past in the background, or know that the child that you’re talking to is crying the whole way through, or that an abusive parent is shouting at them.

For Childline counsellors, this has meant thinking in a different way about what it means to be an active listener. It means making no assumptions, asking detailed questions, and remembering to convey the things that would be apparent on the phone but are lost in text – like the fact that you are still there, still listening, that the last message may have sounded blunt but that’s not how you meant it.

This summer, Brennan was supervising when a volunteer answered a webchat from a child at the edge of a motorway, contemplating suicide. “It was so stark because all we had were their words,” she says. And yet the volunteer was able to convince the child to change her mind.

“It’s very slowly, step by step,” she says. “In that case we had to ask where she’d come from, what route she’d taken, how long it took – all while being empathic and caring, recognising she was in such a bad place.”

“This would come across in a few minutes on the phone,” says Clare Bentham, another Childline counsellor, “but on a webchat, especially if the conversation is going slowly or the child is struggling to open up, it can take half an hour.”

That extra time counts. A caller contacts Childline every 25 seconds and it can only respond to three-quarters of them. If more time spent responding to webchats means less time answering phone calls, is that a worry? “We would never ask them to speak on the phone just because it’s easier for us. We need to do what’s best for them,” says Brennan.

It is telling that most of Childline’s highest-risk cases – ones in which there is a substantial or immediate threat to the child’s life – now come through webchat. For children who already have so little control over their lives, choosing text over voice could be as much about autonomy as about a shift in communication habits.

“Putting some of these thoughts and feelings into words can be difficult,” says Robinson. “That’s why people so often talk about being lost for words. But if you’re able to type it, you have a sense that you’re still in control of it.” When Cook was on the rape crisis lines, before texts existed, she says, that need for control manifested itself in other ways: “For some people, it’s a process. First, they may call once and hang up. Next, they’ll speak to you. Two years later, they’ll want to meet you in person.” Texting, then, may be just a different way in.

Ultimately, helpline advisers believe that the power of listening translates no matter how its done. As Brennan puts it: “To have someone who really listens, and really hears – that’s one of the most powerful things in the world.”

• Some identifying details have been changed. Childline can be contacted in the UK on 0800 1111 and Samaritans on 116 123. Calls to both are free and confidential.

In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international suicide helplines can be found at www.befrienders.org.