Shrieking for the advantage: Does grunting affect your opponent?

Last year (2010) at the Bank of the West Classic held on the campus of Stanford University, some of the best WTA players vied for a $700,000 purse and it all came down to the final pair and the stadium was abuzz in anticipation…

That is, until the match started and all of their eardrums were simultaneously ruptured by the inhuman shrieks emanating from both players.  Luckily, with Stanford being an outdoor tournament, the soundwaves were unable to reverberate and the energy was able to disperse, though likely eliminating a few pigeons in a veritable display of feathery fireworks in the process.

Take a look at a clip of the match and see if you can see the feathers drifting lazily down into the crowd…

Fast-forward to today and I’m pretty sure the stereotypically conservative Britons were regretting the new fangled cover they built over stadium court, especially with the ne’er ending threat of rain looming as the same two players approached a potential final showdown this past Wimbledon (2011).  Fortunately or unfortunately this never actually happened as Petra Kvitova overcame the Belarusian banshee (yes, the screeching kind of banshee) to save many an auditory system.

To grunt or not to grunt is a hotly contested debate involving the players, media, officials and fans.  In 2009 at the Wimbledon Championships (those British, always on the cutting edge) for example the officials pondered whether or not to penalize serious screamers.  If you ask me, its likeliness of resolution is approximate to the likeliness of dogs and cats sharing strawberries and cream during Sunday brunch the first half fortnight of Wimbledon.  Here, I am about to address this rather touchy subject of grunting, but rather than offer an opinion, I’ll take a look at what science has to offer us about the deal.

It’s worth first noting that most recommendations state that 85 decibels for 8 hours is reasonably safe for humans to endure.  Maria Sharapova has been recorded at 109 dB.

Scientifically, it can be argued that attention and performance when related to something like grunting is actually desirable.  Think of it this way, your opponent is hitting a ball and bellowing at you to pay attention to the ball they are striking.  Makes some sense, but is this true?

That seminal study

A recent (Sinnett and Kingstone, 2010) – and apparently first ever study to look at grunting – was published in PLoS1 this past July.  Interestingly, it appears to suggest that a returned shot served up with a platter of shriek may indeed slow an opponent’s reaction time and may also induce said opponent into making more mistakes.

A few (N=33) undergraduate students from University of British Columbia were asked to watch players hitting on a video screen, then asked to judge the direction of a series of shots (left or right) as quickly as possible.  Each shot was either easy or hard (with video ending either after follow-through or at contact), and was either silent or accompanied by a semi-artificial moderate grunting (read: NOT a recording of the Russian or her like) noise.

Lo and behold, what the researchers found were increased reaction times of ~21ms (easy) or 33ms (hard) and more directional mistakes ~3% (easy) or 4% (hard) during the semi-artificial grunting noise.

Of course it’s easy to argue many things, as no study is ever perfect.  For example, because this was a controlled setting, how will this actually translate to the court? Did these students have any tennis playing experience, as this might confound some of the analyses?  But if you think about it, it does seem more complicated physiologically and psychologically speaking to compute trajectories and track down balls while you’re playing.  Tennis is a game of inches, after all so the effects could potentially be fairly profound on that level.  According to the report, “…if a very conservative estimate that a professional tennis shot travels at 50mph during a rally, a 21-33ms response delay equates to a ball travelling two extra feet on every shot before an opponent can respond.”

Throw in Andy Roddick’s ~140 mph serve and you begin to get the idea.

It’ll be interesting to see what the two academics cook up in their follow-up research.  It seems perhaps obvious and plausible to imagine that high level players will have psychologically invented ways in which they can buffer themselves against screaming while lower level players might have less experience with screamers and therefore more trouble with the screaming (I have difficulty imagining a club-level player letting primal screams loose at frequencies and decibels to rival the top WTA players).

But then again, it was also arguable that a grunting opponent might help you focus.

In the meanwhile, what if Roger and Rafa had what it took to rival the WTA’s top grunters?