It was the American golfer Fred Couples who earned the nickname Boom Boom in the 1990s with his explosive tee shots. But golfers who use titanium clubs in search of similarly long drives beware: those booming shots may not be good for your hearing.
A study in the latest issue of the British Medical Journal found that modern thin-faced titanium golf clubs produce a noise loud enough to damage the sensitive hairs of the inner ear. Provocatively titled "Is Golf Bad for Your Hearing?" the study focused on the case of a 55-year-old man who developed tinnitus and hearing loss in his right ear after playing golf three days a week for 18 months with a thin-faced titanium driver, the King Cobra LD. After ruling out age-induced hearing loss and damage from exposure to other loud noises, the patient's doctors at Norfolk and Norwich University Hospital in eastern England decided to test his golf club.
Doctors gauged the sound produced by the patient's club, along with five other titanium clubs, and compared it with that of older-generation steel clubs. A measuring device was positioned 5.6 feet (1.7 m) away from a golf pro at an outdoor tee approximating the distance between a ball and a golfer's closest ear. Doctors found that all six titanium clubs exceeded safe limits, while only two of the six steel drivers posed a hazard.
Although noise-induced hearing loss typically occurs from continuous loud exposure, it can also result from high-intensity "impulse noises," such as gunshots or explosions. According to Dr. Malcolm Buchanan, one of the report's authors, the safe limit for impulse noises is 110 decibels. The titanium drivers all exceeded this limit, with one club cracking out 128 decibels. (See the full results here.) The noise measurements would have been even higher at an enclosed driving range, Buchanan said.
Thin-faced titanium clubs use a trampoline-like effect to propel the ball down the fairway. In 2002 the United States Golf Association banned drivers from competitive play if they were deemed to have too much of a trampoline effect, which might give an unfair advantage. But the trampoline effect also causes high-energy rebounding of the club's metal, resulting in the trademark "crack" that Buchanan thinks injured his patient's hearing. "What we've found is thin-faced clubs, both conforming and nonconforming, produce noise loud enough to damage hearing," he says.
Buchanan says it is too early to call for a ban on such drivers or for golfers to give up the new clubs they got for Christmas. (Acushnet Europe, maker of the King Cobra LD, said it was reviewing the study but declined further comment.) There have been no population studies to date, and, while golf may be a popular game among retirees suffering from age-related hearing loss, there has been no indication of increased inner-ear damage among younger, healthier players. That may be because the titanium clubs have become popular only in the past decade, and ultra-thin-faced clubs even more recently (it can take several years of exposure to impulse noise to produce a noticeable hearing impairment). It's also possible that golfers have suffered slight hearing loss without even realizing it. There's precedent in another sport: in 2002 a study of 150 competitive tennis players over the age of 35 found that nearly half had developed rotator-cuff injuries, but many never knew it because the damage did not cause any symptoms.
Buchanan says he plans to test the hearing of the world's top golf professionals at the British Open in 2009, "which should give us a better idea of the dangers of frequent use." Until further study is completed, he recommends that golfers who use modern titanium drivers wear earplugs as a precaution advice that may not be as onerous as it sounds. After all, earplugs can protect golfers not just from the crack of the club but also the more harrowing sound that often follows: a splash.