The Sliding In Technique for Selective Mutism: A Parent's Guide

If you've done any reading about selective mutism interventions in the UK, you'll have come across the sliding in technique. It's the cornerstone of the Selective Mutism Resource Manual by Maggie Johnson and Alison Wintgens, it's what most NHS speech and language therapists will recommend, and it generally works. When you can make it happen, though — as it's a huge logistical undertaking.

What is the sliding in technique?

The sliding in technique is a form of stimulus fading. It starts with your child talking freely to someone they're comfortable with — usually you — in a quiet space at school. Then, very gradually, a new person is introduced into the room while your child keeps talking.

The key word is gradually. The key is to get the child using voice with you first, which might require a closed door. Then, you open the door. Then, the new person (e.g. a teacher) might start outside the door. Then pop in and out to grab a pen quickly. Then sit at the back with headphones on, then sit at the back absorbed in something with headphones off. Then inching a little closer. Then joining in. Each step is only taken when your child is relaxed enough at the current one.

When it works well, your child barely notices the shift. They're absorbed in whatever game or activity you're doing together, and by the time the teacher or keyworker is sitting beside them, they've already been talking in their presence without realising it was a big deal.

Once your child is comfortable talking with the new person there, you start to slide out until your child is talking to the keyworker without you there at all.

It's elegant. It's evidence-based. And it's built on a principle that applies to everything in selective mutism: change only one variable at a time, and never more than your child can tolerate.

Why it's a bigger ask than anyone admits

Here's what the textbook doesn't prepare you for. To run a sliding in programme properly, you typically need:

1. A parent, grandparent, or someone they talk to who can come into school two or three times a week, for around 30 minutes each time, for several weeks.
2. A teacher or teaching assistant who is consistently available during those sessions.
3. A quiet space in the school that's reliably free for those sessions AND is large enough for someone to slide in and out of the back of.
4. A school that understands what you're doing, why the sessions need to be protected, and why cancelling at short notice can set the whole thing back — and will work around all the safeguarding protocols with you.

If you work, even part-time, blocking out the time for school interventions three times a week is a genuine sacrifice. If the school doesn't have a spare room, you might be bumped by meetings or other interventions. If the teacher assigned to slide in gets pulled for cover, the consistency breaks. And if your child's school hasn't encountered selective mutism before — which is common, given how rare it is — they may not understand why this particular programme needs to be treated differently.

Pulling it off feels like a lot of stars to align. And to me it felt like such an uphill climb that pulling it off would actually put too much pressure on me, which my child would pick up on. Which is why I chose a different route.

However, if you have a school willing to work with you on this — go for it. The research points to it being really successful, and so do the team at Confident Children who largely prescribe this as the way to overcome selective mutism.

What happens when sliding in isn't possible

This is where I want to be honest about something that doesn't get said enough in the UK selective mutism world. When the sliding in technique wasn't fully available to us, I didn't want to advocate harder or push harder, because we were in a busy and quite small London school that genuinely weren't set up with big enough rooms.

So this is where I pulled all the global frameworks into my AI tool, told it our limitations, told it all about Phoebe, and had it synthesise a bespoke plan for us.

And what I found was the US approach — specifically Dr Elisa Shipon-Blum's excellent work on the Social Communication Bridge, which maps a child's communication across stages from non-verbal engagement through transitional communication (sounds, whispers, a verbal intermediary) to full verbal communication.

The critical difference is this: the US model recognises whispering as progress. A legitimate stage. A child who whispers to a friend, or to a teacher during a game, is moving across that bridge, and it's a genuine rung on the ladder.

The traditional UK approach, as outlined in the Selective Mutism Resource Manual, treats whispering with more caution. The concern is that a child can become comfortable at the whispering stage and not move beyond it. The other concern is that whispering is bad for the throat and is still an anxious behaviour. There's a logic to that. But in practice, when your child goes from frozen silence to leaning towards a friend and whispering the name of their doll, telling them that doesn't count feels wrong. It's a genuine breakthrough, and the UK framework has no space for it — and I wasn't happy with that. My daughter took a huge, brave step forward, and the UK material suggested she was nowhere and we needed to go backwards.

What we actually did instead

When the formal sliding in programme wasn't available in the way we needed, I took my plan synthesised from a blend of frameworks and put that to action instead. I used the principles — small steps, one variable at a time, the child always knowing what's coming — but adapted them to the time I had, what the school could give me, and most importantly what Phoebe was ready for.

I devised my own interventions, checking all my ideas against the framework with my AI tool and sparring with it for ideas, pushing for better ones. I pretty much broke ChatGPT and upgraded to the most expensive version of Claude and started to get some really, really good stuff. (This is the tool I've now rebuilt for anyone interested to use. I'm afraid I have to charge for it as it costs me in AI tokens, but I hope it is priced affordably.)

So, with my evidenced-based new bespoke plan signed off by the teachers, we started two sessions per week with the school. We started with games with the teachers, following the S-CAT communication bridge model, generalising Phoebe's whispers from my ear, to the table, to the teacher. Within three months she was directly whispering to the teacher. These were games where communication was built into the activity rather than being the point of it, starting with Uno or Guess Who, and as her confidence grew I was bringing in the ice cream stand from home and a ton of pound coins and playing shopkeeper. The teacher became a familiar, safe presence through play rather than through the formal sliding in structure. And gradually, Phoebe started whispering to her.

I also used the brave steps talking ladder approach at home, practising brave talking before bedtime in silly pretend games. And the playdates became a parallel track — building confidence with peers outside the school setting so that it could eventually feed back into school.

Another thing I believe was super important was that I changed my own language and started to talk to Phoebe about her brave voice coming out soon, and did some personal work to remove my own anxiety about it and replace it with a total conviction that she will talk one day soon. Whether or not you believe in visualisation or manifestation, it doesn't really matter — but I believe my confidence is catching. I started to do talking practice with Phoebe too, and pretend to be someone, and she would say who she wanted to practise talking to. This is a long way from a year ago when she didn't want to talk to anyone.

Finally, I also added in some community practice and started doing structured art activities with a friend and neighbour and her children, and started to take my daughter out and about to shops more. I also stopped covering for her when someone would ask her a question — instead holding a moment of uncomfortable silence and smiling at her, saying "would you like to tell me?" Then just accepting whatever comes.

The point is: sliding in is a brilliant technique, but it's not the only route and there is so much more that you can do. I think it's possibly the fast track, but it's very costly on time and resources. And if your circumstances don't allow it, you haven't failed. You can just dial up on community practices, the location ladder, and work with the school on what can be facilitated instead. The good news is that while this is super time-intensive, once they have overcome it, you won't be going in anymore.

The UK vs US gap that parents should know about

The UK's Selective Mutism Resource Manual is widely considered the gold standard for intervention. And it is excellent. But its position on whispering can leave parents feeling like their child's progress doesn't count if it's not full voice.

The US Social Communication Bridge model explicitly includes a transitional stage — Stage 2 — where sounds, whispers, and verbal intermediaries are all recognised as movement towards speech. Not as a place to get stuck, but as a real and meaningful step forward. And that resonated with us.

The UK approach gives you rigour and structure, like a ladder with big rungs. The US approach gives you the smaller rungs in between, and permission to celebrate the in-between too. I used both, and the combination is what worked for us. And I know I wouldn't have been able to blend both without the help of AI, which is quite an interesting use case for it.

If your child has started whispering, that is progress. Full stop. The goal is still full voice, and you don't want to stay at whispering forever. But a child who whispers after months of silence has done something courageous, and that deserves to be acknowledged.

If you're about to try sliding in

A few things I wish someone had told me:

Ask the school early about space and availability. Don't assume it'll be sorted — get a specific room and time confirmed before you start.

Be prepared for it to take longer than you expect, so that if it only takes a few weeks you will be delighted rather than discouraged.

Have a backup plan. If sessions get cancelled or the space falls through, what will you do instead? Having an alternative approach ready means a disruption doesn't become a crisis.

Read the Selective Mutism Resource Manual if you can. It's written for professionals but it's readable, and understanding the theory behind what you're doing makes you a better advocate for your child. Or, my AI tool will make this easy to digest in simple language if you prompt for it.

And if sliding in isn't available to you at all — because of work, because of school logistics, because of anything — know that there are other evidence-based approaches. Lowering pressure has to come first regardless, and from there, the route forward might look different to the textbook. Everyone's journey will be different because every child is unique and the settings you need help within may be different.

SM Pocket Coach can help you work through what's possible in your specific situation — your child's school, your availability, your child's current stage. You describe the reality, and it helps you build a plan that actually fits.