Advances in Physical Education
2012. Vol.2, No.4, 148-152
Published Online November 2012 in SciRes (http://www.SciRP.org/journal/ape) http://dx.doi.org/10.4236/ape.2012.24026
148
The Influence of Crowd Noise upon Judging Decisions in
Muay Thai
Tony Myers1, Alan Nevill2, Yahya Al-Nakeeb1
1Newman University College, Birmingham, UK
2University of Wolverhampton, Wolverhampton, UK
Received August 14th, 2012; revised September 15th, 2012; accepted September 30th, 2012
Background: Home advantage has been demonstrated across a number of sports, yet questions still re-
main over the causes of the phenomenon. Crowd effects on sport officials have been one mechanism
proposed in the literature. This study attempted to investigate the impact of crowd noise on home advan-
tage by examining the influence of crowd noise on the judgement decisions of Muay Thai officials.
Method: Using a repeated measures design, 10 experienced Muay Thai judges observed a video of a
Muay Thai contest in two different conditions: one with and one without crowd noise. Judges recorded
the number of strikes each competitor made using mechanical counters with a comparison made between
conditions. Results: Judges awarded 1.23 more strikes on average in the presence of crowd noise when
compared to the no crowd noise condition. Crowd noise influenced some judges greatly but other far less.
The results from a within subject ANOVA analysis suggested the differences between noise conditions
were statistically significant (F(1,39) = 4.513, P = .04, η2 = .104) as was the home advantage effect
(F(1,39) = 4.087, P = .05, η2 = .095). Conclusion: Crowd noise increased the scores of Muay Thai judges
resulting in an advantage to the home competitor. Possible reasons for the findings include informational
conformity, the use of a noise heuristic, cue learning or perceptual errors. Avenues for future research are
offered.
Keywords: Home Advantage; Crowd Noise; Decision Making; Officiating Bias; Muay Thai
Introduction
Historically, sports spectators appear to have held the belief
that they can influence performance, as early as 216 BC, Poly-
bius suggested that a cheering crowd influenced the outcome of
a boxing match (Guttmann, 1986). This belief appears to be an
enduring one. Strauss (2002) found in a survey of 10,063 spec-
tators at an American football match held in Germany, that
61.2% of those who responded felt spectators exerted a strong
influence on the outcome of American football games. Along
with the positive influence supporters’ perceive that their
cheering may have on their player’s performances, they also
presume that their taunts and boos can distract the away team
and influence referees’ decisions (Wolfson, Wakelin, & Lewis,
2005).
Home advantage research suggests that sport fans’ assump-
tions may have some foundation. Nevill, Newell and Gale
(1996) found that absolute crowd size was positively related to
the home advantage in English and Scottish soccer. They exa-
mined crowd factors associated with home advantage in Eng-
lish and Scottish soccer matches and concluded that the home
crowd influenced officials’ decisions. Home advantage appears
to decrease with referee experience, with referees of different
experience varying significantly in awarding yellow card and
penalties (Boyko, Boyko, & Boyko, 2007). The mechanism
postulated for this difference is crowd noise.
A number of researchers have chosen to use video evidence
to investigate crowd noise effects on sports officials’ decisions.
Nevill, Balmer and Williams (2002) used a quasi-experimental
design to examine if the presence or absence of crowd noise
would influence officials’ assessments of the legality of 47
challenges/incidents during a recorded English Premier League
match between Liverpool and Leicester City. The study in-
volved referees watching and assessing various tackles and
challenges recorded on videotape and found that the presence
of crowd noise had a significant effect on the decisions made
by the referees. The officials (n = 40) viewing the challenges
with background crowd noise were in close agreement with
those of the match referee and awarded significantly fewer
fouls (15.5%) against the home team when compared with
those watching in silence. The author’s found that there were
no real differences between conditions in how many times offi-
cials penalized the away team, suggesting crowd noise reduced
the number of fouls awarded against the home team rather than
increasing the number of infractions called against the visiting
team. A similar study was conducted recently by Unkelbach
and Memmert (2010) but instead of using video footage from
the same match, they instead used 56 foul scenes from 56 dif-
ferent soccer games. However, their results differed from those
of Nevill, Balmer, and Williams (2002) in that they found an
increase the number of yellow cards awarded to the away team
rather than fewer challenges awarded for the home team when
crowd noise was present.
The observed effects of crowd noise found by in a laboratory
setting have been supported by findings in a “real world” set-
ting by Pettersson-Lidbom, and Priks (2007). In 2007 the Ital-
ian government forced the football clubs that had stadiums with
deficient safety standards to temporarily play their home games

T. MYERS ET AL.
without spectators (Pettersson-Lidbom & Priks, 2007). In total
24 games were played without spectators and this allowed Pet-
tersson-Lidbom and Priks the opportunity to make a direct
comparison with games played with a crowd. They were able to
compare the decisions made by the same referee in games with
no spectators at all, and with many thousands of spectators.
They made comparisons of the number of punishments (fouls,
yellow cards and red cards) awarded by the referee. The find-
ings suggested Italian referees punished away players more
harshly and home players more lightly when the games are
played in front of spectators. The authors suggested this was
evidence of social pressure applied to officials by the crowd
who consciously modified behaviour. In a recent qualitative
study involving semi-structured interviews of five soccer refe-
rees the referees reported they did not feel the crowd influenced
them in any conscious way, but they acknowledged crowds
may influence their decisions in an indirect manner (Lane,
Nevill, Ahmad, & Balmer, 2006).
While the impact of crowd noise on officials’ decisions has
been demonstrated using different methodologies, the mecha-
nism for this is still largely speculative. Explanations for the
phenomena can be considered from different theoretical per-
spectives, with explanations ranging from social conformity to
cognitive biases. The social conformity explanation centres on
referees and judges conforming to the views of the majority of
spectators in attendance when making certain decisions. The
majority view is generally clearly discernible by a referee or
judge when officiating, particularly given a vocal partisan
crowd. Several studies conducted in a sporting context have
demonstrated that judges are influenced by conformity effects
(e.g., Scheer et al., 1983; Vanden Auweele et al., 2004; Boen et
al., 2006, 2008). These studies have focused on what has been
labelled the conformity effect or the tendency of judges to adapt
their scores to be similar to the scores of their colleague judges.
However, it could be argued that in certain circumstances
judges may adapt their scores to the views of supporters in a
similar way.
Conformity may be the result of either normative influence
or informational influence (Deutsch & Gerard, 1955). It has
been suggested that individuals’ motives for conforming in-
clude accuracy, self-related factors and other-related factors
(Pool & Schwegler, 2007). Cialdini and Goldstein (2004) im-
plied people conform because of a desire for accuracy, affilia-
tion or maintaining positive self-concept. In the case of judges
and referees it is possible that one or more of these influences
may impact on their decisions. Certainly it appears that most of
the time people have multiple motives and informational and
normative conformity occurs simultaneously (Stangor, 2004).
A number of authors have suggested motivational hypothe-
sises associated with conformity to explain for their findings.
For example, Nevill and colleagues (2002) suggested referees
award fewer fouls as they wished to avoid displeasing the home
crowd, thus conforming to the views of majority of supporters.
In a similar vein, Sutter and Kocher (2004) suggested while
soccer officials attempt to balance pleasing governing institu-
tions by being impartial with attempting to please the crowd,
home bias results from the crowd’s more immediate influence.
A plausible alternative explanation is that officials use crowd
noise as a heuristic, by providing additional information outside
of the actual evaluation criteria to simplify the judgement task.
Simon (1990) has described heuristics as “methods for arriving
at satisfactory solutions with modest amounts of computation,
(p. 11)”. These mental short cuts have been associated with the
automatic and unconscious functions of the mind. Stanovich
and West (2000) proposed that humans have two mental sys-
tems; one that is largely unconscious, automatic with a propen-
sity to makes quick intuitive decisions, and a second encom-
passes the other slower more deliberate contemplation involved
in analytic intelligence. Tversky and Kahneman (1974) demon-
strated that in particular situations the automatic intuitive sys-
tem uses a heuristic to assist in a difficult judgment, such as the
instantaneous decisions performed by sports officials.
While such heuristics play in a role in reducing the effort re-
quired by a particular task and can be beneficial in a number of
situations, they also causes predictable biases (systematic errors)
in judgement (Shah & Oppenheimer, 2008; Tversky & Kahne-
man, 1974). In making a decision, a sport official may errone-
ously place equal or more importance on the auditory informa-
tion from the crowd as they do on the visual information from
the observed action, causing a biased judgement that is influ-
enced by the vocal support of the crowd.
In combat sports such as boxing and Muay Thai, judges have
to make an assessment of the quantity and quality of blows
delivered. One of the tasks required to achieve this is to deter-
mine if a blow delivered by one contestant makes contact with
an appropriate target area on their opponent’s body. They have
to do this while at the same time assessing a blow’s effective-
ness. This is not always a straightforward task. Not only are
blows delivered very quickly but a judge’s view may also be
obstructed by corner posts, the referee or the boxers themselves.
Any of these factors lead to a level of visual ambiguity that
could allow influence by the sound information provided by a
crowd cheering on or just after delivery.
The possibility of crowd noise influencing the decisions of
Muay Thai judges is potentially greater than the effect demon-
strated on soccer referees (Nevill, Balmer, & Williams, 2002;
Pettersson-Lidbom & Priks, 2007; Unkelbach & Memmert,
2010). The average number of attacks used in an elite Muay
Thai during match has been found to be 183.5 (±27.45) (Myers
& Nevill, 2008). As such, during each round a Muay Thai
judge has to make numerous subjective decisions, deciding if a
particular blow is effective and if it strikes an appropriate target
(Myers, 2007). It is quite common to see a “home town” fighter
being cheered enthusiastically with every kick, punch, elbow or
knee delivered, whether these successfully land on target or not.
If crowd noise influences soccer referees decisions when view-
ing taped tackles. It seems a distinct possibility that the judg-
ments made by Muay Thai officials could also be influenced by
crowd noise. Balmer, Nevill, & Lane (2005) found home ad-
vantage in European championship boxing and a similar effect
may also be evident in Muay Thai as a result of crowd noise.
The aim of the present study was to explore the effect of
crowd noise on the scores awarded by qualified Muay Thai
judges and if this resulted in any home advantage effect. To do
this we used a repeated measures design similar to that used by
Balmer et al., (2007) to investigate crowd noise effects on soc-
cer referees. However, rather than investigating the influence of
noise on soccer referees, we assessed crowd noise influences on
qualified Muay Thai judges. It was hypothesised that crowd
noise would results in judges awarding inflated scores to the
contestant receiving the greater level of crowd support and this
would result in an advantage to the home competitor.

T. MYERS ET AL.
Method
Participants
Following a priori power analysis (see analysis subsection
for details), ten qualified and highly experienced Muay Thai
judges were recruited from the UK (n = 7) and Thailand (n = 3)
to take part in the present study. Institutional ethical was gained
and all participants gave their informed consent to take part in
the study prior to any testing commencing.
Test Video and Apparatus
A Muay Thai fight videoed from the perspective of a judge
from a single angle involving a fight held a stadium in Thailand
between two high ranking competitors was projected onto a
screen using a video-projection system. The eventual winner of
the bout (the home boxer) had the greatest vocal support with
the greatest number of cheers over the course of the bout (70
cheers associated with kicks, punches and knees thrown). Ne-
vertheless, to ensure a representative experimental design and
replicate what is generally the case in an actual competition
environment, the other competitor (the away boxer) did have
some crowd support (44 cheers). Noise level was measured
using a digital sound level meter at 73dB (A) at 2 m. Blows
were recorded using two mechanical hand tally counters with
the counter display covered by electrical insulation tape to ob-
scure the recorded count score from participant.
Procedure
A counterbalanced repeated measures design was used with
the judges being randomly allocated to either a noise condition
first followed by a no crowd noise condition or vice versa; no
crowd noise condition and then a crowd noise condition. This
was done to reduce the possibility of order effects. Each judge
observed the video with the crowd noise audible (the crowd
noise condition) and with a low level of white noise (no crowd
noise condition). After each round of the bout, the video was
paused and scores for each boxer recorded. There was a mini-
mum of two days between trials.
Preceding the start of the first trial instructions were read to
participants. These instructions advised the participants that
they would be watching five rounds of a Muay Thai bout twice,
in two separate trials; one after the instructions were given and
a second after a two-hour period. They were asked to register
strikes delivered by both boxers as accurately as possible using
two hand counters; one counter held their left hand and the
other in their right hand. They were informed that one counter
should be used to record the successful strikes of one boxer (red
corner boxer) and the other counter the scores of the other
boxer (blue corner boxer). They were told to do this by pressing
the relevant counter once each and every time they observed a
punch, kick, knee or elbow delivered by landing on the other
boxer’s body or head. They were advised that they would not
be informed of any of the scores they had recorded until both
trials had been completed to avoid any anchoring effect.
Participants were then given a demonstration and questioned
to determine if they understood the procedure. After this they
were told they would begin a three minute trial (one round of a
different Muay Thai bout) so they could familiarise themselves
with the procedure. Each participant watched the complete bout
(5 × 3 minute rounds) in both conditions and registered strikes
with no other participant present.
Analysis
We designed the experiment with a .8 probability of finding
a significant difference should such a difference exist in our
population of interest. To this end we conducted a priori power
test using G power 3 software to determine appropriate sample
size (Erdfelder, Faul, & Buchner, 1996) for background and a
description). Using an alpha level of .05, 1-β set at .8, with a
partial 2 .15 (an effect we considered represented a meaningful
difference). The calculation suggested ten participants were
required to achieve this. Descriptive statistics were calculated
for the noise and no noise conditions. A repeated measures
ANOVA was conducted with two within subject factors, noise
and boxer. The within subject factor noise had two levels, noise
and no noise. Similarly, the within subject factor for boxer also
had two levels; home and away. Partial eta squared was used to
determine the size of effect.
Results
There were differences in the main effect of crowd noise vs.
no noise (Table 1). However, the standard deviations were
large suggesting sizeable variations in judge’s scores (Table 1).
Interestingly, while 8 judges awarded higher scores in the
crowd noise condition, two judges awarded higher scores in the
no crowd noise condition.
The estimated marginal means between the crowd noise (M =
14.66, with 95% confidence intervals from 12.12 to 17.21) no
crowd noise (M = 13.4, with 95% confidence interval from
11.34 to 15.46) conditions suggest that in the presence of crowd
noise, judges on average awarded 1.23 more strikes than in the
no noise condition. The repeated measures ANOVA suggested
these observed difference was statistically significant for the
crowd noise conditions to a .05 alpha level (F(1,39) = 4.513, P = .04,
2 = .104). The noise-by-home vs. away boxer interaction was
also statistically significant to a .05 alpha level (F(1,39) = 4.087,
P = .05, 2 = .095).
Discussion
The presence of crowd noise did have an effect on the deci-
sions made by the qualified Muay Thai judges and this resulted
in a home advantage. Although the differences were small in
terms of a noise effect, they were statistically significant. The
partial eta squared result for the crowd noise effect suggests
that that 10.4% of the variance in the scores awarded by judges
is attributable to crowd noise, and 9.5% of the variance being
attributing to crowd noise influencing home advantage. Overall
crowd noise resulted in judges awarding 1.23 (5%) more strikes
Table 1.
The means and standard deviations of judges’ scores in noise and no
crowd noise conditions.
Conditions
Boxer
Corner No Noise Noise Difference in Means
Red 17.1 (±9.77)
15.43 (±8.18) 1.67
Blue 12.23 (±6.65)
11.38 (±5.24) .85
150

T. MYERS ET AL.
on average in the presence of crowd noise. This supported the
hypothesis that a crowd can have an influence on officiating
(Nevill & Holder, 1999; Nevill, Balmer, & Williams, 2002;
Unkelbach & Memmert, 2010) and this resulted in a home ad-
vantage, with the interaction between the boxers (home v away)
resulting in a significant effect.
We believe the absence of a real crowd means normative so-
cial conformity influences are an unlikely explanation for the
results of our study. Nevertheless, there are several possible
explanations for the findings, which while have different theo-
retical foundations. Firstly, informational conformity could
have played a role (Deutsch & Gerard, 1955). When a judge
was viewing somewhat ambiguous exchanges during the bout,
they may have used information from the crowd to help them
determine the success or otherwise of a particular blow landing.
For example, when a competitor’s body is turned away from a
judge and they see a kick initiated but not actually land, the
crowd’s cheer may well provide additional information and,
rightly or wrongly, result in that judge considering the kick to
have landed on target. Informational influence has been dem-
onstrated in judging sport previously (Boen et al., 2008) al-
though in that case the influence of other judges rather than a
crowd.
A further explanation of the findings is the possibility judges
used a “noise heuristic” (Kahnerman & Tversky, 1996). Given
judges are required to make an almost instant decision on
whether a blow landed or not, and the criteria for deciding that
can be reasonably complex, judges may well have fallen back
on schemas they had previous used by applying a “mental short
cut” with noise used alongside other signals they had learned to
associate with a scoring blow. In a similar way judges may well
have used noise as a cue, something convincingly argued for by
Unkelbach and Memmert (2010) in their recent paper. They
postulated that sports officials learn to associate particular cues
such as crowd noise to a particular decision in a particular con-
text. Arguing that judges or referees might equate similar audi-
ence reactions with different outcomes, suggesting that crowd
noise may lead to more-positive evaluations in figure skating
and conversely a higher probability of a yellow card for fouls in
soccer. In the case of the present study, judges may have
learned to equate the crowd’s cheers with a blow landing.
Interestingly there were very different responses to crowd
noise for different judges in our study. For some judges crowd
noise had the effect of increasing their scores quite dramatically,
for others a relatively small increase was observed, and yet for
two others the complete reverse was found with much higher
scores in the no crowd noise condition. While a counterba-
lanced design was employed in an attempt to minimise any
order effects, since the participant’s viewing of the same bout
was only separated by two days, anchoring bias may have im-
pacted on the results in participant’s observations in subsequent
conditions. The anchoring bias is a phenomenon in which deci-
sion makers adjust too little from their initial judgments as ad-
ditional evidence becomes available and this account for some
of the individual differences found (Tversky & Kahneman,
1974). However, that fact that crowd noise appears to have
differing effects on individual’s judgement decisions may well
be explained plausibly by individual-level factors other than
anchoring.
Decision-making performance can be influenced by differ-
ences in both the experience of making a decision and the abil-
ity to cope with affective states during decision-making (Seo &
Barrett, 2007). Certainly positive affect appears to be related to
better decision making when compared with negative affect
(Forgas, 1995; Isen, 2000). Although given the experimental
conditions it is unlikely that emotion was influential in the re-
sults of the current study. Individual differences in responses to
crowd noise are consistent with previous findings.
Research is needed in this area in an attempt made to identify
the particular factors that are involved in producing individual
decision responses to crowd noise. Lane et al. (2006) have pro-
posed a Referee Decision Scale; a 9-item scale principally de-
signed to assess individual themes and ideal-decision making
themes. We suggest that this could be used to compare referee
decisions between crowd noise and no crowd noise conditions.
This scale, and modifications of it, appears to offer the oppor-
tunity to help determine particular individual level factors in-
volved in evaluative decisions in the presence of crowd noise.
However, until more is known regarding individual differences
and crowd noise interactions and without clearly being able to
identify which judges may be vulnerable to the influence of
crowd noise, it can be argued that that Muay Thai judges should
use some form of nose cancelling earplugs to avoid the influ-
ence of crowd noise.
Before concluding, it is important to consider any methodo-
logical limitations that may have contributed to our findings.
One limitation of the present study is the fairly moderate simu-
lation of the “real-life” situation in our experimental design.
Without a real interactive crowd the possibility of normative
social conformity was reduced. It would be problematic to use
the type of repeated measures design used in the present study
during an actual live bout. However, it would be possible to
have several judges viewing several different bouts in different
conditions. This would increase validity significantly with par-
ticipants being surrounded by an actual crowd in the noise con-
dition. However, it should be noted that since external and rep-
resentative experimental design considerations are independent,
increasing the degree of such “real world” representation might
not increase external validity.
In conclusion, the results from the present study suggest that
crowd noise does affect Muay Thai judges’ decisions when
judging Muay Thai. This adds to previous findings in others
sports and point to the potential for crowd noise to contribute to
the home advantage through referee or judges’ decisions. In the
present study, judges on average awarded more points in the
presence of crowd noise and this was generally in favour of the
home competitor. Several explanations could explain this, in-
formational conformity, the use of a noise heuristic, or cue
learning where judges have previously associated crowd cheers
with a scoring blow. Equally, it may be that judges’ perceptual
accuracy was compromised by crowd noise, the differing re-
sponses the result of unidentified individual differences.
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