Dog, deer or Djokovic?

Mike Lotinga - July 2017

As the Wimbledon 2017 finals approach this weekend, it’s the time of year to revisit the annual debate: to grunt or not to grunt?

Tennis ‘grunting’ is a popular but controversial subject, such that it even has its own Wikipedia page. Maria Sharapova’s shrieks have even been (wrongly) compared with a chainsaw. Many have called for grunting to be banned, generally assuming that it is distracting to opposing players and therefore against fair play. But is it? And are there any other advantages to grunting that have contributed to its apparent proliferation? What parameters of grunting might influence any effects conferred?

Well, as you might imagine, these questions have all been studied. A lab experiment in the US examined response times and judgement errors in subjects watching tennis shots with and without simulation white noise bursts during ball strikes. The results were “unequivocal”: noises interfered with the ability to react correctly, and were associated with significant increases in both measures[1]. It’s debatable whether white noise is a suitable and comparable sound to substitute for real vocal grunts of course, especially considering that white noise makes an effective warning alarm signal and so is perhaps more attention-grabbing.

A more realistic study examined the effect of tennis players’ grunts on measured serve and forehand stroke force and velocity. This showed that there were significant increases in both when players grunted compared with non-grunting plays[2]. Of course, the causality in the relationship in this case is not beyond doubt; grunting could have increased shot force and velocity, or a harder shot may entail a grunt, however the subjects recruited included a mix of ‘grunters’ (players who believed grunting gave an advantage), and ‘non-grunters’ (those who held no such belief), suggesting the results do indicate an advantage caused by the grunts. Interestingly, as part of the experiment setup the subjects had to ‘calibrate’ their grunts to give a consistent level!

Most recently, as discussed in a BBC article[3], the sound character of tennis grunts has been investigated in the UK. The study by Sussex University considered the possible relationships between grunt pitch and a range of variables, finding that match outcomes were associated with grunt pitch sequences[4]. In other words, as the match progressed towards its conclusion, the outcome could be predicted by the pitch of grunts – higher grunt pitch being associated with increased stress and fatigue, and eventual match loss.

Since grunting arrived in professional tennis, courtesy of Monica Seles, some high-profile figures have condemned it as ‘cheating’. It does seem that the evidence supports an advantage conferred to grunters and disadvantage to the opposing player. On the other hand, if everyone grunts then the playing field is perhaps levelled, and the winners may be the spectators who gain a more exciting match!

Whichever view you take, and despite some official efforts to manage the issue, it does seem like grunting is not going to be banned outright in the foreseeable future, so we’ll probably get to have the same debate this time next year…

Enjoy your strawberries and don’t forget the suncream

[1] Sinnett, S & Kingstone, A, 2010. A preliminary investigation regarding the effect of tennis grunting: does white noise during a tennis shot have a negative impact on shot perception?. PLoS ONE, 5 (10), e13148.
[2] O’Connell D G, Hinman, M R et al, 2014. The effects of “grunting” on serve and forehand velocities in collegiate tennis players. Journal of Strength and Conditioning Research, 28 (12), 3469-3475.
[3] An extract from which forms the title of this blog entry!
[4] Raine, J, Pisanski, K et al, 2017. Tennis grunts communicate acoustic cues to sex and contest outcome. Animal Behaviour, 130 (2017), 47-55.