Emma Thompson has a new look, but the sound is familiar.
Impervious to interruptions, immune to hesitation, it whoops and loops in elaborate conversational circles before finally giving way to a re-application of peachy-coloured lipstick. "Bugger. Worn it all off. Think I've been banging on too much," she says.
Banging on is one of the things Emma has done brilliantly down the years. She not only has opinions on everything, but the verbal virtuosity to ensure they are fully and inescapably broadcast.
In the past, her fondness for saying what she thinks has landed her in trouble, with critics labelling her "the most annoying woman in Britain", but the actress isn't listening, and today, reassuringly, there is something else she wants to talk about.
First, though, that new look.
The familiar, layered blonde hairdo has given way to a shorter, silvery pixie-cut, and around Emma's slinky, yoga-toned form is draped a multi-tiered, ankle-length outfit from the cult London design house Egg, whose customers include British Prime Minister, Theresa May.
Emma is approaching 60, a Dame of the Empire, and the style seems to say that she has reached a more serious stage of her life.
The roles, too, reflect a subtle change. In her new film The Children Act, adapted from a novel by Ian McEwan, she plays a High Court judge, confronted by moral dilemmas at work and a sex-starved husband at home.
To prepare for the part, Emma spent months watching up-close how the law works, and found many of her comfortable assumptions challenged.
"We were able to go behind the scenes at the High Court and the Old Bailey, and I found it completely fascinating," she says. "What hits you first is how arcane it seems, like being in a kind of secret society, with all these ancient rituals and mystical rules. Yet judges have this extraordinarily important, responsible job, and it is humbling to watch them working with such professional dedication, but also with compassion and understanding, knowing that their judgements can affect people so viscerally that their whole lives may depend on it.
Emma's character, Fiona Maye, sits in the Family Division of the London High Court, a place described by McEwan as "teeming with strange differences, special pleading, intimate half-truths and exotic accusation".
The pressure of work is affecting her marriage to Jack, a laid-back academic (played by Stanley Tucci), who complains that they haven't made love for nearly a year, and announces his intention to have an affair.
Barely has Fiona digested this shock, than she is plunged into a case involving a 17-year-old Jehovah's Witness, who, supported by his parents, is refusing to have life-saving blood transfusions.
Wreathed in powerful emotions and beset by conflicting ideas of moral justice, Fiona must, essentially, decide whether the boy lives or dies.
Emma says the film appealed because she couldn't think of another one with a female judge in a leading role.
"The law is a deeply patriarchal, hierarchical and rigid institution," she huffs, "so for a woman to get through the door, she has to be doubly brilliant. I got to know a couple of these women judges and they are extraordinary. I'm not suggesting a woman judge will handle a case differently, but her journey to the bench will have been different. It's a heavy old world to break into, and you have to prove yourself even more.
"I think it changes you. When you are sitting up there, looking down on everyone, with that power to rule, you feel godlike. But when Fiona is away from that 'place above' and she is sitting in her flat with her husband she can't hear him, and it is as though that godlike quality has made her deaf."
Emma is uncharacteristically quiet for a moment. The film, which takes its title from a landmark 1989 Act of Parliament, giving courts rights to safeguard children's welfare by overruling the wishes of parents, has clearly made her think. And to reflect on whether she would have reached the same decision as Fiona.
"Well, look, I'm a leftist, feminist, libertarian white atheist, so I'd obviously have thrown the whole thing out of court without a second's argument," she hoots.
"But that's because I'm me, and I'm not sitting in judgement. When I'm being Fiona, my job is to show that we need to think about these things, and ask how we find a way to respect a different point of view. It's always a good thing to question your own views. Keep questioning. Better than being certain about anything. Certainty is death."
Not that Emma has ever been shy of expressing an opinion.
Activism, she says, is in her blood. Even at The Camden School for Girls – a favoured destination for the daughters of well-heeled, liberal-thinking parents – she went on ban-the-bomb marches, supported striking coalminers and collected money for Greenpeace.
At Cambridge University, where she became the first female member of the celebrated Footlights theatre troupe, she shaved her head and embraced feminism, and was, she says, "loud and angry".
She has since unloaded on everything from Brexit to the Israel-Palestinian conflict, described climate change sceptics as "bonkers", been sprayed with manure by an angry farmer during a fracking protest, and created a polite stand-off between those who regard her as a national treasure and those who caricature her as the champagne-quaffing queen of the cause-mongering showbiz "luvvies".
She was shaped by a bohemian childhood, the daughter of Eric Thompson, creator of an oddball 1960s children's TV programme, The Magic Roundabout, and his formidable Scottish actress wife, Phyllida Law.
The family home was a hive of creative energy, filled with writers and actors like Sir Alec Guinness, who told Emma the facts of life when she was eight.
She cheerfully accepts the irony of having burst out of all this early radicalism to become famous for playing upstanding women with posh voices in period dramas.
"It's definitely odd," she nods. "I hadn't really thought about it like that, but it's true, I'm the diametric opposite of many of the parts I've played. I remember my mother once screaming at me: 'Oh, no! You're not going to play another GOOD WOMAN IN A FROCK!' And I thought, 'Goodness, is that really me?' But things have changed a little as I've got older – I mean recently I've played some absolute nutjobs, totally bonkers women."
Which leads directly on to one of Emma's enduring preoccupations: "The thing is that roles for women are so few and far between. I don't mean actual roles in actual films, I mean roles that mean something within our story structures, and there's really not a lot of choice. You don't get a lot of... oh, maverick women freedom fighters, so the palette for women in what I call heroic roles is not very big, and it only exists at all in terms of having a woman do the same thing as a man, so how many choices do we have?
"There's the bad mum. Done that. The good mum. Done that. What else? I've just played a late night TV chat show host [in the forthcoming film Late Night, co-starring Amy Ryan], and there are no female late night TV chat show hosts, so that's new. We have to create our own stuff. If I'm talking to women, I say to them, you have to find new stories and you've got to write them yourselves, and if you can't write them find someone who can."
Emma's damehood arrived earlier this year with the Queen's birthday honours list, elevating her to the ranks of such theatrical matriarchs as Judi Dench and Maggie Smith. In receiving it, she made a point of promising to continue banging on.
"It's a huge honour," she announced. "I've always wanted to be able to refer to myself as a dame. Small D. Dame with a capital D is even more thrilling. I plan to go on being very difficult, just in case anyone was wondering if it might shut me up."
Why should it? Even those who claim to find Emma annoying would struggle to deny that she's been one of the great adornments of modern screen and stage. Always destined to be an actress, she began making a name for herself in the 1980s with TV and theatre roles, but it was her Oscar-winning performance as the engaging, enigmatic Margaret Schlegel (a character who still fascinates her) in Merchant Ivory's 1992 production of Howards End, that made her an international star.
By this time she was married to Kenneth Branagh, the brightest young light of the British theatre, and the couple – fondly known as "Ken 'n' Em" – were fêted as the successors to Laurence Olivier and Vivien Leigh.
The marriage, though, was less of a triumph than their collaborations, and they broke up after six years, when Kenneth began an affair with actress Helena Bonham Carter.
Emma was plunged into depression, and has not worked with Kenneth since, although she has publicly forgiven Helena, who she calls "a wonderful woman".
For the past 15 years she has been married to actor Greg Wise, whom she met during the 1995 production of Sense and Sensibility, which won her a second Oscar.
They live with their 18-year-old daughter, Gaia, in the same leafy north London street Emma grew up in. In fact, the entire neighbourhood sounds like a veritable warren of Thompsons, with mum Phyllida living a few doors away, Emma's younger sister, Sophie, also an actress, round the corner, her adopted son Tindy up the road, and various nephews and cousins dotted close by.
They all seem to get on a storm, although Emma is cautious about offering advice on successful relationships.
"You've just got to hold on through the bad bits," she says, "and if you get through to the other side it's always better. I think people in long, happy marriages tell a lot of fibs, like 'Yes, it's been marvellous,' whereas I say 'No, sometimes it's been awful.' I hope it carries on, but we don't know. We're very clear. We say, 'Well, this is nice, isn't it?' We don't take anything for granted."
When Gaia was born in 2003, after IVF treatment that Greg later described as "brutal and upsetting", the couple learned they were unable to have any more children.
Two years later they met Tindyebwa Agaba, a 16-year-old former child soldier from Rwanda, who had been sleeping rough in London's Trafalgar Square. They decided to help, taking him into their home, guiding him to a place at one of Britain's top universities, and while they have never formally done so, they consider him their adopted son.
During these years, Emma scaled back on work, appearing mostly in supporting roles in smaller scale projects. She spent a lot of time writing at her remote cottage in the Scottish Highlands, and home-schooled Gaia.
The worrying news for her fans is that she thoroughly enjoyed the time off and is hungry for more."I feel very fortunate to have had my career, but I'm definitely thinking about slowing down," she confides. "It would be a bit mad, actually, to get to nearly 60 and not be thinking about it.
"You have to be honest. It's not like I'm 30 any more, and I'm only still going now because I've been lucky, and I've never been ill, and people still want me to do things. I'd like to do more writing, more projects with women, but I definitely don't want to go on working all the time. I really don't want to do that. I just want to live."