Mummy's gone for a wee-wee. A bit blunt? We can be blunter if need be. Look. Here (shuffle, shuffle) is a nice colour photograph of a toilet. Now do you see, Rosie? Mummy's gone for a wee-wee.
None of this stops Rosie crying, since she's determined to carry on as a matter of principle. But at least she knows where mummy is. Life's such a puzzle just now for both Rosie and her mother that any missing bits of the jigsaw - even photos of the plumbing - are gratefully received.
As toddlers go, Rosie has been unlucky. She hardly hears a thing, and what she has heard so far makes little sense. On the other hand, for a toddler with a hearing impairment, Rosie has been lucky. For she and her mother have found this haven of good sense in a baffling world.
There's a massage parlour up the street and a few blocks east the InterCity trains thud into Euston. But once through the security gate and past the man who guards the door, it's all sweetness and white walls at the Christopher Place Speech, Language and Hearing Centre.
Quiet, too, when you consider there are 35 children between the ages of three months and five years here most mornings. That's on account of the acoustic wadding behind every wall. The doors are a decent weight, too, with round viewing panels that make every room a shared space.
Who paid for Rosie's haven - for the tall windows that contrive to be safe, the tiny wooden tables and chairs that contrive to be comfortable? There's a list of 37 benefactors on the very first wall you see, with the Rose Foundation at the head and the Liberal Jewish Synagogue at the foot - and somewhere in the middle, David Hockney and Lord Forte.
"The fundraising was so successful," says Angela Harding, the director at Christopher Place, "because people couldn't believe a centre like this did not exist."
Harding had been a teacher of the deaf for 25 years when she was approached by Andrew Jaye, the father of a hearing-impaired child. The Jayes were devastated, first by the diagnosis, but then by the fact that nothing happened afterwards. "They were left in limbo."
On a visit to America, they found a centre where they got support and therapy for their daughter. "They came back and asked if I would set something up here." In 1991, Harding and Jaye formed a registered charity. Four-and-a-half years later, Christopher Place admitted its first children - and its first parents.
"Partnership with parents is one of the hallmarks of what we're doing, " says Harding, "Our single clearest target is helping parents to communicate appropriately with their children."
She talks about developing "a cycle of communication" through support and guidance, but at the same time encouraging parents to be parents again. "Often," she says, "they suddenly feel thrown into the role of teachers and therapists. It's am- azing how quickly what should be a fun and spontaneous relationship gets distorted."
Usually it is the parents who first detect a speech or hearing problem. "But sadly," says Harding, "they are often advised to disregard their doubts. They are told, 'Don't worry, they'll grow out of it.' This is totally irresponsible, and often it is done because there is nowhere that would address the fact that a child has been diagnosed early. We hope that setting up a centre like this will help put a stop to it."
Not that early diagnosis is much use without immediate treatment. Harding says: "It's all very well putting hearing aids on to children, but so what? It's the intensity and quality of the treatment that is going to turn them around."
Although there are a number of children at the centre receiving rehabilitation after cochlea implants, and an increasing number with intermittent hearing loss caused by fluid in the ear, the majority are profoundly deaf. Yet, with early diagnosis and immediate treatment, "you really can tap into these children's residual hearing and achieve miraculous results".
At Christopher Place, this treatment is not the preserve of any single discipline. As well as specialised teachers, the centre employs a speech and language therapist, an occupational therapist, an educational psychologist and a dance and music therapist. Professional works with parent, teacher works with therapist ... and in the middle are the children.
Those who attend the centre's morning sessions are immersed in a language-rich environment of songs and stories, music and art, all linked in a fortnightly cycle of themes. "All the time," says Harding, "we're watching for ways of inputting appropriate language."
Group work is punctuated with one-to-one therapy sessions in which individuals are withdrawn for short periods. Parents, meanwhile, agree to a minimum number of formal meetings with staff. At the same time, they are encouraged to involve themselves informally with everything that goes on at the centre.
In the afternoons, Christopher Place runs more as a clinic, with a range of teachers and therapists usually offering one-to-one therapy in hour-long sessions.
The centre takes children from a11 over the country, making use of video for families unable to attend frequently. Parents from far afield can still be given ideas about how to work with their children. "A two-hour session can set them on the right track," says Harding. And video helps the centre work hand-in-hand with other professionals where a child is also attending a mainstream nursery.
The cost of treatment can be met by parents, by local authorities (currently eight children are supported in this way), or by the Christopher Place Child Sponsorship Fund.
Now the building is complete, says Harding, donations are channelled into sponsorship. "It has always been our aim that no child will be refused because of finance. I would love to see the fund paying for a significant percentage of children within the next five years."
And with that, the director is off into the corridor to investigate a crying baby. "Sorry," she says, "but it's the Christopher Place way."
Christopher Place Speech, Language and Hearing Centre. Tel: 0171 383 3834.