Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Aural Assault on the Links?
- Martin Tepper, Pierre Lamontagne, Steven Schofield and David Carpenter (29 December 2008)
-
Re: Aural Assault on the Links?
- Malcolm A Buchanan (31 December 2008)
-
Coefficient of restitution
- Peter W Hart (5 January 2009)
-
Letter to author
- Ian T Logan (5 January 2009)
-
Re: Aural Assault on the Links?
- Jonathan R Roberts (5 January 2009)
-
Is golf bad for your hearing?
- James R Scott (8 January 2009)
-
So, what was his handicap?
- Barry M Gold (9 January 2009)
-
Why is Titanium louder? Material's analysis
- Dietmar Giljohann (9 February 2009)
-
tinnitus and golf drivers - It happened to me?
- Louie Kish (22 August 2009)
|
|
|||
|
Martin Tepper, Chief, Communicable Disease Control Program, Canadian Forces Health Services Group Headquarters Ottawa, Canada, K1A 0K6, Pierre Lamontagne, Steven Schofield and David Carpenter
Send response to journal:
|
We enjoyed the paper by Buchanan et al (1) regarding a possible link between hearing loss and the use of "thin faced titanium golf drivers". However, we have some observations that erode confidence in the tentative conclusion of such a link in this case: a. proper golf form entails that, when hitting a golf ball, head position is lined up directly at the golf ball and remains steady until after the club head impacts the ball. If hitting a golf ball with a titanium driver is to be responsible for the hearing loss, one would expect symmetrical hearing loss, unlike the right sided asymmetry seen in the paper. Admittedly, it may be that, probably like many golfers, the patient tends to rotate his head prior to the driver-to-ball impact; this could then lead to an asymmetrical hearing loss on the side closest to the ball (as well as an "errant stroke"). Videotaping the patient while driving golf balls would help to settle this matter. b. with impulse noise (as from the driver-to-ball impact), the brunt of the noise acts within the first 10 milliseconds after the impact. In the paper, the "Ping G10" driver recorded the highest noise level at 130 decibel. If using the 3 dB exchange rate (2) to determine safe exposure levels (the most stringent method), one would be allowed to hit 200 drives within a 24 hour period before hearing protection becomes necessary; this would be quite unusual during a round of golf although it could occur during practice driving ("hitting buckets of balls"). One of us (PL, an audiologist and a competent and avid golfer) has proposed a research project in which he will play three rounds of golf per week (similar to the patient) using the loudest titanium driver found in the paper during the entire summer. Audiograms would be done before the experiment starts, weekly during the experiment and after the experiment is over. We are awaiting ethical and managerial approval as well as funding. 1. Buchanan MA, Prinsley PR, Wilkinson JM and Fitzgerald JE. Is golf bad for your hearing? British Medical Journal 2008;337:1437-1438 2. National Institute for Occupational Safety and Health. Occupational Noise Exposure: Revised Criteria 1998, page 25 Competing interests: None declared |
|||
|
|
|||
|
Malcolm A Buchanan, ENT Specialist Registrar Norfolk and Norwich University Hospital, UK
Send response to journal:
|
We thank Tepper et al. for their useful observations from our study, and acknowledge that both ears should theoretically be exposed to the same level of noise, provided that the head remains static at the point of impact. However, there may be small movements of the head, best demonstrated by a video, as suggested. Occasionally in fact, when I was swinging some of the louder clubs, I experienced tinnitus in either ear. The Professional golfer did not report any tinnitus at all, suggesting that he already had some noise-induced trauma to his cochleae from hours of exposure to "hitting buckets of balls" in the range. An audiogram or measurement of his otoacoustic emissions would be useful to investigate this further. We are planning to measure the hearing levels of Professional golfers who use louder clubs to see if they are affected in the same way as our patient. We shall be interested to see your results following a few months of summer golf, but would like to point out that our patient played regularly with his King Cobra LD club for 18 months, and that at the end of this time, found the noise so unbearable he had to throw it away! Competing interests: None declared |
|||
|
|
|||
|
Peter W Hart, Locum Renal SHO Glasgow Royal Infirmary
Send response to journal:
|
In the interests of promoting golfers' understanding of physics and thereby enhancing their game, I feel compelled to comment on a minor error in the interesting case report by Buchanan et al. The authors explain the regulation maximum coefficient of restitution of a golf club of 0.83 as meaning that a club head velocity of 100 mph will cause the ball to travel at 83 mph. However, if this were true, the club head would have to either pass through the ball, or decelerate quite substantially to less than the ball's speed, resulting in a very nasty kickback to the golfer's arms. In fact the coefficient of restitution is calculated by (V2f - V1f)/(V1 - V2) where V1 and V2 are the scalar velocities of the two colliding objects (here, the club head and ball) before impact, and V1f and V2f are the velocities of the respective objects after impact. Using this formula we find that a golf club head with a coefficient of 0.83, travelling at 100 mph, will impart a velocity of 183 mph to a golf ball, assuming zero deceleration of the golf club at impact (which is fairly safe where one object far outweighs the other). Competing interests: I share Mark Twain's view on golf, and hope that the association of perplexing calculations with the sport may act as a form of aversion therapy, and hasten its extinction. |
|||
|
|
|||
|
Ian T Logan, GP ST1 Nottingham City Hospital NG3 6AA
Send response to journal:
|
From: itlogan@hotmail.com
Dear Dr. Buchanan, I have just enjoyed reading your article in the BMJ "Is golf bad for your hearing?". Initially I wondered what the suspected cause may be but then when I realised you were investigating the sounds made by the new drivers I was not surprised at all by the findings you made. I remember testing the King Cobra speed LD driver with the stiff shaft a few months ago in the range. The first time I hit the ball I thought I had broken the club the noise was so loud and disconcerting. Suffice to say I did not buy it purely because of the noise even though the results were spectacular. I wondered whether when you tested the sounds made by the drivers it was done in a range or outdoors? I think this may make a difference to the noise levels reaching the ear. Most driving ranges have wooden/metal panels surrounding the golfer which obviously reflect the noise back towards the ears. I suspect there's no evidence to suggest that professional golfers who are at the end of their careers have significantly worse hearing than control groups because the older drivers didn't produce such a loud noise. Perhaps though there will be evidence in the future when people who play very regularly with new drivers for a long period have significant hearing damage. I shall keep my ear to the ground so to speak. Regards, Dr. Ian Logan Competing interests: None declared |
|||
|
|
|||
|
Jonathan R Roberts, Lecturer in Sports Technology Sports Technology Institute, Loughborough University, LE11 3QF
Send response to journal:
|
Having conducted research into the sound of a golf impact for several years, I read this article with interest. Although the focus of our research was on sound quality, the loudness of the sound is a major factor and the increases in sound pressure level (SPL) of driver impact sounds has been noticeable as the materials have changed from wood, to steel and then titanium, with the corresponding increases in clubhead size and decreases in shell thickness. The risk to hearing briefly crossed our minds whilst visiting a manufacturer that made use of robots to test golf equipment. One employee’s task was to place a ball on the tee before each shot and a back-of-a-cigarette-packet calculation suggested he should be wearing ear defenders. There is, however, a major difference between this situation and that of the ‘average golfer’; his ears were much closer to the sound source and the robot was capable of hitting shots at a faster repetition rate than a person and for much longer periods. During a round of golf, a player will probably only use their driver once every 10 minutes; even during a practice session, few players will hit more than 20 -30 shots with their driver. To add to Tepper et al.’s observations, the measured level of ~130 dB in this paper is for a professional golfer. We have recorded similar levels for elite players but these golfers are capable of generating clubhead speeds of up to 120 mph. The average golfer will only generate speeds of about 85-90 mph and this results in a significantly reduced SPL. In addition, binaural recordings of impact sounds measured at the entrance to each ear canal of a right handed golfer have also revealed higher levels at the left ear compared to the right, presumably because the sound sources (clubhead and ball) are moving rapidly away from the right ear, if the head is assumed to be pointing toward the ball at impact. Is is also interesting to compare these levels with the regulations set out for the workplace. In the Control of Noise at Work Regulations 2005, measures are required once peak levels reach 135dB(C). This is the lower action level, there's an upper level at 137 and a limit value at 140. In each case, different obligations are placed on the employer. It's not that easy to translate from the workplace to the golf course but there are times when the golf course is the workplace e.g. for driving range staff, golf instructors etc and perhaps it would be worthwhile including these people in the debate. Competing interests: None declared |
|||
|
|
|||
|
James R Scott, Compliance officer, BBC London
Send response to journal:
|
I read this news story with great interest, and the above posted comments and thank you for the research. I also purchased a King Cobra driver due to spectacular results at the driving range and on the course, but quickly had doubts (much less than 18 months, more 18 hits!) about the gunshot type noise levels in both scenarios (other golfers would regularly look from far away for the source of the noise). I concur with the above respondant who mentioned that driving ranges with their metal structures tend to amplify the sound yet further. I would be very keen to see the research carried out under those circumstances, I also believe that may explain why certain ears are more affected than others due to the reflected noise. I used to note how my left ear would be whistling after a hitting only a few balls at the range, having persisted with the club due to its' expense, I certainly wish I hadn't as I also feel I have suffered permanent hearing damage/tinnitus as a result of it. At the time it became clear that it was definately causing problems I stopped using the club and consulted a GP who doubted the link. I really think that this research is important and that the manufacturers and the R+A should act further. Competing interests: None declared |
|||
|
|
|||
|
Barry M Gold, Managing Partner bmgcollc - 92612
Send response to journal:
|
Give me a break! As someone mentioned earlier, a proper swing means holding your head down and still and then looking up after a proper follow through. Therefore, I don't see how it's possible that both ears would not be affected, if at all. I use a Ping G10 Driver, developed with the help of the "Cray" computer for maximum benefit. I love the sound it makes and the results of using a good golf head design along with the proper shaft. Competing interests: None declared |
|||
|
|
|||
|
Dietmar Giljohann, Engineer Germany
Send response to journal:
|
As a mechanical engineer, I wondered why Titanium is louder than steel and considered two aspects of the materials: Material damping and Young's modulus: 1.) Steel and Titanium alloys have a material damping of approx. 0.1% and don't differ that much. Hence a dependancy on the damping is not expected. 2.) The Young's modulus of steel is higher than that of Titanium and therefore should excite the higher frequencies of the impulse much more than the Titanium club. The higher thickness of the steel club provides additional stiffness. So just from a material's perspective the loss of hearing should be higher for a steel club. Competing interests: None declared |
|||
|
|
|||
|
Louie Kish, self employed - engineer California, 92705
Send response to journal:
|
I just read the article and - perhaps I can attest to the link between golf and tinnitus. I am 58 yrs old, and a "range rat": For years I have regularly hit buckets of balls. My tinnitus started about 5 years ago which is fairly coincidental with the new range and the use of my various titanium drivers. There are days when the tinnitus is worse than others, and in retrospect, many times I noted that it was loudest after a session on the range. A few years ago, there were days when I wore earplugs on the range thinking that perhaps there was a link. My web searches at the time came up empty. What got my attention this time was not the noise. Rather, I just read an article that perhaps it was the stress to the neck area caused by the golf swing. That made sense because sometimes the tinnitus peaks after lying in different positions (I'm a couch potato as well). It was this focused web search that lead me to your article. If anyone is doing further study on this, please count me in on the testing. Competing interests: None declared |
|||