Introduction
The World Health Organisation (WHO) recognises voluntary recreational exposure to high-intensity sounds, known as unsafe listening, as an important modifiable risk factor of hearing loss.1–3 The burden of unsafe listening is high and can occur via exposure to several sources of high-intensity sounds, such as personal listening devices and entertainment venues.2–4 Another potential source of unsafe listening that has received less attention is video gaming, including electronic sports (known as esports).3 Gaming may be a source of unsafe listening because individuals often play video games at high-intensity sound levels and for several hours at a time. Furthermore, gaming is one of the most popular leisure activities worldwide, with an online source estimating there were over 3 billion gamers worldwide in 2022.5 Identifying common sources of unsafe listening is important because it is possible to reduce unsafe listening practices through known public health practices and by developing and implementing global policies focused on promotion of safe listening practices.6
Research suggests that recurring, or even a single, exposure to high-intensity sounds, could permanently damage the auditory system, commonly referred to as sound-induced or noise-induced hearing loss.7–9 Early signs of sound-induced hearing loss include (1) transient or permanent tinnitus, which can be defined as a perceived sensation, often ringing or buzzing, in the absence of an external stimulus, (2) hyperacusis, which can be defined as enhanced sensitivity to sound, and/or (3) difficulties understanding speech, particularly when background noise is present.1 10 Exposure to high-intensity sounds has been tied to 'hidden hearing loss,’ which exists without measurable permanent changes to audiometric thresholds but can present as the symptoms described above.11 12 It has been hypothesised that hidden hearing loss is common among young people given that many young people engage in unsafe listening practices.4 12 Importantly, exposure to high-intensity sounds among young people might also make them more vulnerable to developing age-related hearing loss later in life.13 14 It is important to note that permanent hearing loss and/or tinnitus caused by high-intensity sounds can be prevented. Identifying modifiable risk factors of hearing loss and/or tinnitus, such as unsafe listening, can promote its prevention, thus reducing the burden of these conditions on individuals and society.
There are several ways in which unsafe listening may occur when playing video games. First, individuals can play video games at home through a gaming console, personal computer (PC) or on a smart device (eg, smart phone or tablet). Second, video games can be played over local area networks in gaming centres or PC rooms, which are locations that offer computers or gaming consoles primarily for the purpose of playing multiplayer games. Headphones are frequently used, and individuals may increase the volume to higher levels than their preferred listening levels to overcome the background noise that is common in these settings. While gaming centres and PC rooms exist worldwide, the vast majority are in China and other Asian countries. Third, electronic sports, termed esports, involve competitive, organised gaming and are rapidly growing in popularity. Some esports players are professional gamers, and therefore may practice for many hours a day, often using headphones, and compete regularly in online or in-person competitions or tournaments. Esports competitions or tournaments can be available to spectators either online or in-person at esports arenas. These esports arenas livestream virtual esports events, and some also host esports competitors in person during which spectators watch the competitions. Therefore, both esports gamers and spectators may be at risk for unsafe listening.
Permissible levels of recreational sound exposure can be estimated from equivalent occupational noise exposure limits, which are defined as an average sound intensity (eg, 80 decibels (dB)) over a period of time—for example, a 40-hour working week).7 15 Permissible noise exposure limits vary slightly by region or by regulatory agencies or organisations and the target population’s age.7 16 17 Here, we focus on noise exposure limits published by the International Telecommunication Union (ITU) in collaboration with WHO.7 Sound intensity (dB) is measured on a logarithmic scale and there is a time–intensity trade-off, known as an exchange rate, for permissible levels and duration of exposure, and therefore, permissible levels of noise exposure change drastically by sound level. For example, based on a permissible noise exposure level of 80 dB for 40 hours a week with a 3 dB exchange rate, the permissible exposure time of an 83 dB sound is 20 hours, of an 86 dB sound is 10 hours, of a 92 dB sound is 2.5 hours and of a 98 dB sound is 38 min per week.7 15 18 For children, permissible noise exposure levels are lower and can be based on a permissible noise exposure level of 75 dB for 40 hours a week. Under this definition, children can safely listen to sound at an 83 dB sound for approximately 6.5 hours, an 86 dB sound for approximately 3.25 hours, a 92 dB sound for 45 min, and a 98 dB sound for only 12 min per week.7
Using an average sound intensity to define permissible levels of sound exposure is common; however, an average does not define whether impulse sounds, which can be defined as sound consisting of bursts lasting less than one second and with peak levels at least 15 dB higher than the background sound, are included in the average.19 In occupational settings, impulse noise may have negative effects on hearing, beyond what can be explained by exposure to non-impulse noise, and may lead to acute acoustical trauma.19 20 In general, the audio of video games comprises of (1) sounds of similar intensities, and (2) often (particularly in shooter games), impulse sounds. Permissible exposure limits for impulse sounds vary but are approximately 100 dB for children and 130–140 dB for adults.17 19
Taken together, it is plausible that gaming may be a source of unsafe listening. Yet, it is not known whether gaming may pose a risk to auditory function. Efforts towards prevention of global hearing loss would benefit from identifying sources of unsafe listening, which may include gaming. Therefore, the objective of this systematic scoping review is to synthesise current evidence related to relationships between gaming and the potential risk of hearing loss and/or tinnitus.