'AND this," says Dame Evelyn Glennie, "is a wrenchaphone." The instrument resembles a xylophone, but with bars made from worn-old wrenches.

"It's unbelievably tuneful," says Glennie, picking up a pair of slender mallets and tapping out a flurry of bright, clear, chiming notes using her famously supple wrists.

Nearby is a frame from which are suspended a number of old, cracked bars used on a marimba. "Most people throw them out," she observes of them. But she was inspired to have them turned into their present form by the sight of a traditional instrument in South Korea, many years ago.

"Watch your ears," she smiles as she clashes the bars together. The sound, if it caught you unawares, could make you jump out of your skin, but as the bars settle they make a pleasant tinkling sound, like wooden wind-chimes.

This room in Glennie's Cambridgeshire office is full of percussion instruments of every imaginable description, including the world's largest pedal timpano. Dozens more instruments lie upstairs; many others can be found at her home. Looking around the room, taking in the concert posters and framed photographs on the walls, and watching Glennie at work, you get a sense of who she is: a restlessly innovative and ambitious musician, collaborator; and commissioner of new works; the holder of three Grammy awards; the world's first full-time solo percussionist.

We're here in advance of a programme about Glennie that will be screened on BBC Two Scotland tonight. It's entitled What Do Artists Do All Day?, but in her case the question seems superfluous. Her diary is packed, and she has a support staff of three. Apart from her musical career, Glennie is a regular motivational speaker, consultant, composer and giver of masterclasses. She's the person you turn to if you're preparing for an exam or want to understand music-business contracts or learn more about improvisation. She has also designed some rather nice jewellery. Little wonder that her website describes her as "one of the world's most eclectic celebrities".

Glennie's story is, of course, well-known. The youngest of three children, she grew up on a farm in Methlick, near Ellon, Aberdeenshire. Her mother was a church organist, her father played the accordion and Glennie, who played piano from an early age, discovered a passion for percussion instruments while at Ellon Academy. The very first album on which she appeared was recorded in 1979 when she was 13 and part of an Aberdeenshire schools band assembled by percussion teacher Ron Forbes. Forbes would later describe his former pupil as "a natural. She has great rhythmic sense, terrific pitch, she's a workaholic, and she's a very ambitious lady".

Glennie's talent was all the more remarkable because, having begun to lose her hearing at the age of eight, she is profoundly deaf and has used her exquisite sensitivity to vibration to forge a lasting career.

Her lip-reading skills are exceptional and Glennie is an engaging interviewee, who delivers her answers crisply and concisely. As Sue Lawley observed of her then Desert Island Discs guest in 1993, her voice is perfectly modulated; it still bears a pleasant trace of her native Aberdeenshire.

Now 49, Glennie has been based in Cambridgeshire for more than 20 years. "I had spent maybe 10 years in London," she tells me, "from the age of 16 to 25 or 26 [she graduated with honours from the Royal Academy of Music in 1985, aged 19], and as the instrument collection was building and the concerts increasing, I found I couldn't function in a one-bedroom flat.

"Property was so expensive, too. I knew I had to move out, and I wanted to be in the countryside. A friend who lived in the [Cambridgeshire] town of St Neots saw a property being advertised and said to me, why don't you take a look? It had an outbuilding, and that was the key for me, really."

Since her career began Glennie has given around 2,000 performances, including the London 2012 opening ceremony, when she led a 1000-strong army of volunteer drummers and also premiered Caliban's Dream on a new instrument, the Glennie Aluphone. On the day we meet, she and her staff have been mulling over tour schedules and discussing visas.

The list of concerts is being added to all the time. Since the What Do Artists Do All Day? camera crew left a few weeks ago, she has flown to New Zealand to appear with the Auckland Philharmonia in The View From Olympus, by the composer John Psathas, with whom she has worked closely. She has been to Dusseldorf for a concert with the city's chamber orchestra. Not every concert invitation receives a positive response, however: she recently knocked back the chance to play in Russia because of the situation in Ukraine.

Is she very selective about accepting engagements? "Yes, definitely. The key question is, 'What is the difference we can make?' Simple as that. When you're young you're saying yes to everything and then you reach a point where you know where your level is for the amount of work that you do, and you need to find out where that is in order to weed things out a little."

Glennie is now looking towards "the next phase" of her career, which involves establishing a centre dedicated to "teaching the world to listen". She has often said that her custom of using her body as a "giant ear" or as a resonating chamber has left her more open to things. She is convinced that compassion, patience and inclusion are all forms of "social listening".

"Teaching the world to listen means you are inviting people to come in and to try to understand - how do you listen? Is there something we can learn in our domestic life, our professional lives? Because most of the time, when I give speeches, it's about listening ... all challenges within companies, within home life, are usually down to listening, and the quality of that listening.

"It's an activity that, as we're engrossed in the internet, we are losing, to an extent. Yet it is the one thing, and the first thing, that happens when we make any decision, because we have to listen to ourselves, really.

"The centre would encompass other people coming in and being trained as regards to, this is what it means to open your body up as a big ear, and how does that change us?"

The centre won't just be for musicians or percussionists. Glennie sees it as a place for masterclasses and talks, where instrument designers or scientists interested in sound can drop by, where young mums can try their hand at some of the instruments on show. "Engagement is what is important," she says.

In terms of her legacy, she says it's important to her that everything that is already in place "can be sustained once I'm long gone. I've never seen my career as simply the player, and retire from that and live happily ever after. My legacy has to do with what communication is, or how we can make that into a personal journey to create a better environment".

Much of this second phase of her career, however, comes down to what she can realistically hope to achieve in the time available. "Physically, you don't know how long you're going to go on for, but I want to be able to support, as it were, a composer and a performer; I think, I'd love to get those elements together, and assist in the commissioning process."

In the past, Glennie has collaborated with Bjork, the pioneering banjo-player Bela Fleck, and the classical pianist Emanuel Ax. "Next year," she says, "we're working with a couple of dance groups, whereby I co-write the score and perform with the dancers. The other day I met with Mark Knopfler; again, that's co-writing a score together … the percussion will be one of the main forces of the score, so it ticks that box of keeping percussion at the forefront."

Glennie has made more than 30 solo recordings, and interpreted everyone from Bartok to James MacMillan and Philip Glass. Her improvisational CD, Shadow Behind The Iron Sun, encapsulates what she does best: tackling, fearlessly, everything from Japanese cup bells and children's sound-toys to car-exhaust pipes cut to different lengths. She recorded all 13 pieces on the first take.

Does she have any albums in the pipeline? She consults a notebook. "We're waiting for two recordings to come out, but I have no idea when. One is with the Albany Symphony Orchestra, in New York - the percussion concerto by Joan Tower. We've also recorded with the Hong Kong Chamber Orchestra, and that's all mallet percussion concertos … marimba, vibraphone, glockenspiel, tubular bells, that kind of thing."

In the days following the interview she will fly to Switzerland to premiere two percussion concertos; on October 25 she will be with the Tacoma Symphony Orchestra, in Washington State, with a programme that includes Ravel's Bolero, Debussy's Nocturnes and the world premiere of Sean O'Boyle's Portrait Of Immortal Love.

Next month sees "a slightly unusual project". A second version of the Glennie Aluphone she first played at the London 2012 ceremony, with its distinctive silver cone-shaped bells, will make its US concerto debut.

As if all that wasn't enough, she is also studying designs for a new Glennie range of jewellery called Resonance. She is keen to develop her line of men's jewellery - "personally, I like a lot of men's jewellery," she says, "even for myself to wear."

Doesn't she have any downtime? "Weekends are usually when the concerts are," she laughs. "There's always a lot of stuff that has to be researched, but I no longer feel guilty at saying, I'm going into the garden, or to mosey around an antiques fair, or just do nothing." Having divorced (from composer Greg Malcangi) in 2003, she describes her current status as "not single, but not married".

Does she ever get back home to Ellon? "Once a year, usually, unless I happen to be playing up there. I had a concert in Aberdeen a few weeks ago, and saw the family then." Sometimes, her brothers visit her in Cambridgeshire: "One of them came down here with his family earlier this year."

On tonight's TV documentary she brings up the R word, saying she is looking forward to retirement. "It will be interesting, it will be one of the most creative times," she says on-camera.

She says now that this may have been in the context of "physically, as a player, when I will retire from actual playing. "That is very clear in my head - that I wouldn't have any problem that, if I felt something wasn't feeling right, or you're not reaching the level you want to be [at] ... because that time will come.

"It comes for every musician, every sportsperson ... I will absolutely retire from playing, but I will not retire from ... "

Everything else?

"Heavens, no," she says, laughing again. "Definitely."

What Do Artists Do All Day? Evelyn Glennie, BBC Two Scotland, tonight, 10pm