When Sioned Williams first realised that her hearing was not all it should be, she was not in mid-flow playing her harp at the Proms, but at home with her husband. “He asked why the radio was on so loud,” Williams says. “It didn’t seem loud to me.”

Williams, principal harp of the BBC Symphony Orchestra from 1990 to 2017, has endured a lifelong struggle with McArdle disease, a rare, inherited, metabolic muscle condition. “I shouldn’t really be able to play the harp at all,” she remarks. On top of that, hearing loss seemed like the last straw. “I told nobody and went to Musicians’ Hearing Services. When they said I’d got a problem in both ears, serious enough to warrant hearing aids, I completely fell apart.”

An alarmingly large number of musicians suffer hearing damage at work. Williams maintains that the situation is made worse by something of a taboo in the profession. Many musicians are reluctant to talk about the problem, and sometimes they demur from protecting their ears at all. “You don’t want to be the one making a fuss,” she says, “and people are scared to be different. They’re also scared of losing work.”

According to a 2015 survey by the charity Help Musicians, professional musicians are four times more likely than the general population to suffer noise-induced hearing loss. Some 47 per cent of respondent musicians reported occasional or permanent hearing problems. Nearly 40 per cent said that they had not sought professional help, believing the issue an unavoidable effect of their work as a musician.

And yet, as Help Musicians points out, “although noise-induced hearing loss is 100 per cent irreversible, it is 100 per cent preventable”.

John*, a violinist with several decades of experience in UK orchestras, preferred to speak anonymously. He says that he has no hearing loss – but he puts this down to his own painstaking efforts to protect himself. He is shocked at how few others do likewise.

“For 25 years, I’ve used a custom-made ear protector in my left ear – in the first violins, most of the sound comes from your left,” he says. “Sometimes I use them in both ears. But often I’m the only one wearing them, and when I first started doing it, people would take the mickey.”

Why would musicians have such a destructive attitude to protecting the sense on which their livelihood depends? “It was thought that you couldn’t hear properly with earplugs in,” John says. “People used to complain about having to sit in front of the trumpets. I’d say, ‘Use ear protectors’. But they’d be convinced that if they did, they wouldn’t be able to hear themselves play.” Custom-made ear protectors, however, can cut down damaging decibels while letting you hear the essential sound behind the racket. “It’s a matter of getting used to it.”

We all start to lose some acuity in our hearing after the age of 20. Actual damage, however, is caused when excessively strong sound vibrations bend the wispy “stereocilia” on top of the hair cells inside the cochlea in the inner ear. While rock musicians tend to have the worst levels of exposure, classical musicians in orchestras or opera are not so far behind.

Sometimes hearing loss is gradual, as in Williams’s case. Sometimes it isn’t. In 2012, the violist Christopher Goldscheider in the Orchestra of the Royal Opera House developed career-ending acoustic shock and permanent hearing damage after some rehearsals in which he was positioned directly in front of a large brass section. He sued his employers and won a substantial payout. The noise levels around him had peaked at 132-137dB. For comparison, a jet aeroplane 250 yards away reaches your lughole at about 140dB.

John says that his own worst experience was playing in a cramped orchestra pit, close to a wall and sandwiched in front of the percussion. The acoustic makes a difference: a large orchestra becomes more dangerous in a small but resonant space. “Even with my usual ear protectors it was unbearable,” he says, “so I got myself those headphones that construction workers wear when using pneumatic drills.”

The celebrated pianist Steven Osborne has suffered from tinnitus since his mid-twenties. “I found I would get some ringing in my ears after practising,” he says. “At first it would go away after a few minutes, and then one day, it just kept going. It was a very high pitch, not loud, but it freaked me out. I went to an audiologist, who helped me get some custom-made earplugs to prevent the damage getting worse. But it never did go away.”

He “catastrophised” at first. “As a pianist, your hearing is your livelihood, and I had no idea how it was likely to progress, how much worse it might get, or if the tinnitus sound would overpower what else I could hear. Apparently that doesn’t happen, but I didn’t know that at the beginning.”

Unlike many others, he has always spoken openly about the problem, wanting to normalise the addressing of this issue. It’s necessary: a recent report from Tinnitus UK suggests that 59 per cent of music professionals suffer from this irreversible condition.

Osborne feels, moreover, that his earplugs have changed his playing for the better. “I used to play a bit too inwardly. Wearing them helped me play as if reaching out a bit more to the audience.”

Trying to imagine the performance from the listeners’ point of view, he has found the distancing effect even more helpful. He describes what it’s like to perform Rachmaninoff’s Piano Concerto No 3, one of the biggest – and loudest – in the repertoire.

“It’s a little bit like Charlie and the Chocolate Factory when Mike Teavee becomes tiny and is projected into the television. With earplugs, it’s almost as if I hear the music more as the audience hears it. I don’t get so obsessed with tiny details and I follow the flow of the music more easily.”

After the EU’s 2003 directives for controlling occupational noise were absorbed into the UK in the Control of Noise at Work Regulations 2005, orchestras had until 2008 to implement them. Among the requirements were spacing out the musicians when possible, putting players of noisier instruments on “risers” to project above rather than at their colleagues, and managing the players’ average duration of exposure to noise.

That can affect the repertoire choices; a late romantic tone poem involving a large, brass-heavy orchestra could be balanced out by quieter pieces. Duration matters: being exposed for about eight hours a day to sounds above 85dbs can damage hearing. In Scandinavian countries, orchestral rehearsals are usually limited to four hours a day; in the UK, it is generally six.

Some orchestras now provide baskets of earplugs to which players can help themselves (“they look like piles of sweets,” John says). Players in front of the noisiest instruments, like the brass and percussion, are often shielded with clear acoustic screens.

Nevertheless, Williams says she has had problems persuading colleagues to use these. “As a harpist, I was always asking for screens. People might say, ‘We can’t because we’re blowing too close to it and the sound’s bouncing back on us.’ But it was already bouncing in my ear all the time, especially with the timpani and percussion. Sometimes my head would shake from the volume.”

Williams required hearing aids; these too are more sophisticated than they used to be. She asked for inner-ear aids, which are all but invisible from the front. Custom-built ones work well, moulded to the individual ear, she says, but she was unable to get them on the NHS. “When I lost one, I was told I could only replace it as part of a pair. But a new pair cost me several thousand pounds. I can’t afford spares, so now I’m terrified of losing them.”

Musicians’ support organisations offer invaluable aid, notably in the form of the Musicians’ Hearing Health Scheme from Help Musicians (the scheme is paused this year, and relaunching in autumn). A small fee provides access to expert assessment, advice and a pair of custom-made earplugs.

Awareness of hearing problems has certainly increased in recent decades, but so have noise levels in the general environment. “I’ll do anything I can to protect my hearing,” Williams says, “but more and more decibels of sound are around us all the time.” The screech, rattle and roar inside the London Underground, for instance, at times well exceeds the UK Health and Safety Executive’s 85dB threshold. Perhaps we should all consider wearing ear protectors now, musicians or not.