IN 1990, Bella Bathurst went skiing in France with some university friends. One day on the slopes she hit ice, crashed and injured her head. She wasn't wearing a helmet.

She returned home bruised but otherwise fine apparently. “It's interesting, almost Cubist,” mused her father when he saw the mess she had made of her face. “You look better like that,” said her youngest sister unhelpfully.

Seven years later, another ice-related head injury. This time Bathurst, now living in Edinburgh and working as a journalist, skidded while driving at night on the outskirts of the capital. Her car hit a hedge and flipped onto its roof.

There seemed at the time to be no connection between the incidents. But a little over a year later, Bathurst found herself sitting in a hospital audiology department in London being told that the combined head injuries had damaged her cochlea – a core component of the inner ear – and that the hearing loss she had been experiencing since the second accident was degenerative and irreversible. In other words she was going deaf. She was 27.

Losing her hearing didn't stop her writing, though. She continued to work as a journalist and in 2000 her first book, The Lighthouse Stevensons, won the prestigious Somerset Maugham Award. She has written several more books since. But even with the hearing aid she had fitted in 1999, daily life became a challenge.

“It was sort of like a general turning down [of volume],” she tells me when I ask her what deafness sounds like. “But that actually makes you more acoustically sensitive because you really can't deal with lots and lots of inputs. So the fact that there's music playing at the same time as someone was talking, especially if that person wasn't turned towards me, I would find really difficult to deal with.”

Without the hearing aid it was much worse. Bathurst would hear only “the exclamation marks”, as she puts it. “The end of a sharp sound. If you banged the chair down, I would hear that”.

But that's not the whole story. After 12 years of deafness – 12 years of the many accommodations and compromises that condition requires and demands – she found herself, in the summer of 2009, sitting opposite another audiologist being given news she didn't ever think she would hear: that her deafness was treatable after all, and that an operation called a stapedoctomy could even reverse it. But she'd have to pay – and travel to France, where the surgery had been pioneered.

We're talking in the cafe of Glasgow's CCA on a showery Friday morning. Bathurst, who lives in London, is in the city for a few days to help renovate a friend's boat. But she's also here to talk about a new book in which she tells this story – about those accidents, living with deafness, the effect it had on her life and her mental health, her investigations into how we hear and why sometimes we don't, her journey through others' experiences of hearing loss and deafness, and the battle to regain her own hearing.

The book is called Sound: Stories Of Hearing Lost And Found. It begins with a stark example of when being deaf can be deadly – a storm-lashed Scottish sailing trip in which Bathurst finds herself unable to understand and respond quickly to shouted commands – and ends with a post-operation Bathurst, now with almost full hearing, enjoying Sir Simon Rattle conducting the Berlin Philharmonic. “I sat there, sound-blasted, while a few bars of Schubert changed everything,” she writes.

In between she delves into the workings of the inner ear in the company of audiologists; talks to musicians such as George Martin, son of Beatles producer George Martin, about the stigma surrounding deafness in that profession; converses with profoundly deaf people to try to understand something about how they experience the world; and has a chilling encounter with a former special forces bomb disposal expert who literally did blow things up for a living.

I start by asking how her hearing is now. “It got re-tested about four months ago and it was even better,” she replies. “Once in a blue moon there's a moment when someone will say, 'Your phone's ringing in another room' and I just haven't heard it. But it's so rare. As far as I'm concerned, it's sort of 20/20.” That, by the way, is not a technical term.

The operations, one on each ear, took place in 2010. And they worked. So for nearly a decade, Bathurst's hearing has been more or less normal. But it's only now, 20 years after she started going deaf, that she feels able to assimilate everything that has happened to her and to put it down in print. As a journalist and writer who is more used to asking questions than answering them, she's evidently much happier on the other side of the table.

“I wanted to write about the subject because there seemed to be so much within sound and hearing that was interesting and it seemed so little explored, but I really didn't want to write about my own experience,” she says. “It was too close for comfort or I hadn't processed it sufficiently. It took me a long time. I kept coming up with book proposals that were talking about the subject but not really about me. Finally I worked myself around to understanding that the only way to tell it was through my own experience, then I could put in all the other bits. But it had to be filtered through me.”

According to the organisation Action On Hearing Loss (AOHL), formerly the Royal Institute For The Deaf, around 11 million Britons have some form of hearing loss. Of these, 60,000 are profoundly and “pre-lingually” deaf, in other words they were either born completely deaf or lost their hearing before they could speak. In her book, Bathurst accords them a capital D. Everyone else is just deaf, or “deafened”.

Breaking down the figures, AOHL estimate that around 40 per cent of the over-50s have some form of hearing loss – this is the generation who grew up listening to loud rock music, remember – and that among the over-70s, the figure rises to 71 per cent.

Bathurst was unusual, however. She was among the 2 per cent of deaf people who had lost her hearing young. Her deafness also came on relatively quickly, leaving her little time to adjust. Her brain tried, but as it did her other senses began playing up. Walking down the stairs in the morning, for example, her nose would be assailed by “phantom smells” such as patchouli oil, rosemary or diesel.

She sought refuge in books (“The great thing with print is it's always the right volume,” she laughs. “You're never going to have to worry about not having understood half the sentence”) and later found a part-time job in a professional developing lab, communing wordlessly with “this endless flow of images … In terms of a compensatory thing for the hearing loss, it worked brilliantly”. It helped that she is also a keen photographer.

But one of the most troubling effects of her deafness was the sense of isolation it caused and the depression that resulted from that feeling. It's a common story among deaf people, where levels of depression are five times higher than in the general population, and four times higher among their partners. Among those born deaf, meanwhile, there are also higher-than-average problems with drug and alcohol abuse, and more cases of personality and behavioural disorders.

The link between deafness and poor mental health is an “absolutely massive” untold story, Bathurst thinks. “Sight gives you the world and hearing gives you other people and that capacity to connect, to hear and be heard, to listen and be listened to. If you take that away …”

Bathurst's deafness, and the “anger and sadness” that went with it, certainly took its toll on her. One relationship ended, she rolled through a series of others and for years there wasn't a day when she didn't think about death. She never intended to kill herself, she says, but at the same time she didn't want to live. “I did often think longingly of more passive exits,” she writes in Sound.

As her friends threw themselves into their home lives, their relationships and, increasingly, their young families, Bathurst concentrated on her work. Asked to describe her defining characteristic during this period, a friend she quotes in the book uses just one word to described his memory of her: hostile. Things came to a climax one Friday night when she turned up at the inpatient department of her local mental health unit asking to be sectioned. Come back Monday, they said.

I ask her what she hoped to achieve by that desperate act. She chews on it for a moment.

“I think it was just about being in a safe place,” she says finally. “I think I wanted people around me.”

A cry for help, then?

“Yeah, absolutely … I think at the time I was in that sort of limbo state, definitely. It lasted on and off for about seven years.

“There was nobody else around me who was deaf. I thought of deaf people – deaf with a capital D – as a totally separate elite group and everybody else with hearing loss was just old, so there was no support. Everybody else treated it like it was a joke. I thought the fact I was exhausted all the time was just because I was lazy so there was [also] a huge element of shame.”

The tiredness, it turned out, was a symptom of the same ear condition which, by 2009, had revealed itself to be not sensorineural, as first thought, but conductive, and therefore treatable. In theory, anyway. The condition itself is called otosclerosis and it affects the middle rather than the inner ear.

The intricate mechanics of the ear, and the complex and multiple problems which can arise within it, mean that Bathurst's case wasn't one of simple misdiagnosis. Certain symptoms of otosclerosis don't always manifest themselves, and if they do there's still only a relatively short window of opportunity for surgeons. Even so, I wonder if she ever feels like she was robbed of 12 years of hearing.

“Someone asked me that the other day: are you angry?” she says. “No, it wasn't anger, it was gratitude because if you think you have an irreversible condition for all of that 12 years and then somebody tells you that there's an operation, I mean it just feels astounding. Incredible. And no matter how well or how happily I'd adapted to it at that point, I still existed within a hearing world and I'd still been hearing for the first 27 or 28 years of my life. So no, I never felt like I'd been robbed.”

In fact, she says, the process of losing and then re-gaining her hearing has been a gift of sorts. Sure, music is still music and sound is still sound, but her understanding of how hearing works and her appreciation of its wonders has increased tenfold. Now “everything I understand about the world and sound is totally informed by my experience of losing my hearing”, she says.

“So if I listen to the washing machine spin cycle I still think it's the most fabulous thing in the world. I wouldn't have felt like that before. And I understand these pieces of jewellery we've got in our heads – and I find that astonishing and miraculous every single day.”

Sound: Stories Of Hearing Lost And Found by Bella Bathurst is out now (Profile Books, £16.99). She appears at the Boswell Book Festival on Saturday, May 13 at 1.30pm. The Sunday Herald is the festival's media partner. For programme and ticket information visit www.boswellbookfestival.co.uk