Football match spectator sound exposure and effect on hearing: A pretest-post-test study
South African Medical Journal
Football fever is rising in anticipation of the quadrennial 2010 FIFA World Cup event. Half a million international supporters are expected to converge on South Africa for the historic event, to be hosted in Africa for the first time. Spectators will be greeted by a distinctively African sporting spectacle uniquely characterised by sounds produced by sports fans blowing the horn-like instrument known as the vuvuzela. 1 Cherished by local supporters, the vuvuzela produces a characteristically
... aracteristically loud, reverberant sound that can be heard for miles around the stadium. In the recent 2009 Confederations Cup held in South Africa, the international football community noticed this phenomenon. 1 Despite complaints from international teams, spectators and commentators about the uninterrupted loudness of the vuvuzela, FIFA approved it as part of the signature 2010 World Cup to be held in Africa. 1, 2 The actual sound output created by the vuvuzela was recently reported to reach dangerously high levels, averaging 131 dB(A) at the horn opening and 113 dB(A) at a 2-metre distance from the vuvuzela. 2 These values exceed international directives on exposure limits in occupational settings. Although there is significant variability in individual susceptibility, prolonged or regular exposure poses a significant risk for noise-induced hearing loss. 3-5 Recreational activities with excessively loud sound levels are an increasingly important public health care concern for developing permanent sensorineural hearing loss. 5-8 We aimed to determine (i) noise exposure levels of spectators at a FIFA 2010 designated training stadium during a premier soccer league match; and (ii) changes in auditory functioning soon after the match. Methods Ethical clearance was received from the University of Pretoria (September 2009), and we obtained permission from the City of Tshwane to conduct the study at the specific stadium. Each participant signed an informed consent form. Study population Spectators at a South African premier soccer league match held in October 2009 at a FIFA 2010 designated training stadium with a 30 000-seat capacity were sampled to participate in the study. Eleven participants (2 female) with an average age of 27.2 years (range 20 -40 years) were drafted for the study. Participants were provided with a free ticket to the match. The left and right ear of each participant was assessed before and after the match. Only one of the 22 ears assessed did not have normal hearing averaged across all frequencies (<20 dB HL) because of a perforated tympanic membrane. As a result, preand post-match hearing data were collected from 21 ears (11 participants). Participants were not allowed to consume alcohol before the post-match assessment was completed. Data collection All participants were assessed by four audiology clinicians within 3 hours before attending the football match. The assessment included an otoscopic examination and tympanometry to rule out external and middle ear abnormalities. One left ear (1/22 ears) was excluded because of a tympanic membrane perforation. All remaining ears of the 11 subjects were tested with pure-tone audiometry, highfrequency pure-tone audiometry, and distortion product oto-acoustic emissions (DPOAEs). Pure-tone audiometry was Objectives. To determine (i) noise exposure levels of spectators at a FIFA 2010 designated training stadium during a premier soccer league match; and (ii) changes in auditory functioning after the match. Methods. This was a one-group pretest-post-test design of football spectators attending a premier soccer league match at a designated FIFA 2010 training stadium in Gauteng, South Africa. Individual spectator noise exposure for the duration of the football match and post-match changes in hearing thresholds were measured with pure-tone audiometry, and cochlear functioning was measured with distortion product otoacoustic emissions (DPOAEs). Results. The average sound exposure level during the match was 100.5 LAeq (dBA), with peak intensities averaging 140.4 dB(C). A significant (p=0.005) deterioration of post-match hearing thresholds was evident at 2 000 Hz, and post-match DPOAE amplitudes were significantly reduced at 1 266, 3 163 and 5 063 Hz (p=0.011, 0.019, 0.013, respectively). Conclusions. Exposure levels exceeded limits of permissible average and peak sound levels. Significant changes in postmatch hearing thresholds and cochlear responsiveness highlight the possible risk for noise-induced hearing loss. Public awareness and personal hearing protection should be prioritised as preventive measures.