Acoustic Comfort in Indoor Sporting Arena for E-Sports Venue: An Analysis of The Determining Criteria and A Conceptual Framework

It is vital that people concentrate and focus on the types of sports and amenities in the context of sports facilities to provide acoustic comfort for players and fans. Thus, influences the positive or negative psychological and emotional impact experience during the sports matches. Esports events are mostly organized in enclosed spaces facilities such as indoor arenas or stadiums, which are spaces where speech intelligibility and noise level determine, to a large extent, the listening comfort or even the safety of the occupants. More noise may distract players throughout the match and during the match, interfering with their performance and communication with coaches if there is no proper sound blocking or insulation. This research will look at critical literature studies of the defining elements and criteria for this occurrence to develop a conceptual framework for how players, coaches, and spectators experienced acoustic comfort in various types of Esports venue. The primary goal of this research is to clarify the differences in Esports venue design and the determining factors that influence human acoustic comfort. As a result, the goal of this study is to create a framework based on the elements that determine acoustic comfort classification in Esports venues. Designers and architects able to utilize this framework as a guide to assist them prepare estimates of acoustic conditions and corrective activities in Esports venue which tailored suited to players, as well as the effects on staffs and spectators, thus create a highly immersive experience.


Introduction
Sports halls, gymnasiums, and swimming pools are huge open spaces intended to survive years of usage for a range of sports and well-designed for the efficient conduct of the indoor sporting activity.Different sporting arenas are designed in various terms of technical outlook for variety of activities either in terms of size, width, volume of the hall or length and the type of materials applied for the arena.As a result, this influences their acoustic performance in order to promote clear communication and provide a pleasant environment for both the players in the arena and the spectators or audiences.
"The atmosphere was just totally unique.I've never witnessed fans making that much noise in 90 minutes" [1].This comment, spoken after a professional football (soccer) match, exemplifies how important stadium noise (typically in the form of external noise generated by spectators) is in the reality of professional sports [2].From here, how music and sound have become so important to the spectator experience, as well as how they may help players perform better.However, not all sports-related noise is pleasurable.Too much noise may irritate fans, negatively impacting their experience.In the other hand, players might feel distracted by noise from the crowds and effected their performance.For these reasons, such a gap in between represents vital indicator for research as shown in Figure 1 on which determining factors and its parameter provides a good sound to achieve acoustical comfort of sports facilities.
Indoor arena or stadia have been utilized for various sports and events, including Esports events, which have gained popularity in recent years [3].However, acoustic comfort in such spaces has not been thoroughly studied, despite its crucial role in determining the overall experience of players, coaches, and spectators.A greater degree of noise can affect speech intelligibility and distract players, affecting their performance and communication with coaches [4].Moreover, it can also affect the safety and listening comfort of the occupants.Therefore, it is necessary to explore the defining elements and criteria for acoustic comfort in Esports venues and develop a framework that can guide designers and architects in preparing estimates of acoustic conditions and corrective activities in these venues.Literature studies have suggested that acoustic comfort is a multidimensional construct influenced by various factors such as speech intelligibility, noise level, and overall ambiance.These factors can determine the classification of acoustic comfort in Esports venues, which may vary depending on the design and layout of the space [5].For instance, the position of loudspeakers, sound insulation materials and the configuration of seating arrangements can affect the quality of acoustic comfort.Therefore, it is necessary to explore the differences in Esports venue design and the determining factors that influence human acoustic comfort [6].The primary objective of this research is to develop a conceptual framework that can guide designers and architects in preparing estimates of acoustic conditions and corrective activities in Esports venues.This framework will be based on the critical literature studies of the defining elements and criteria for acoustic comfort in indoor arenas for Esports events.Moreover, it will explore the differences in Esports venue design and the determining factors that influence human acoustic comfort.As a result, the research will clarify the elements that determine the classification of acoustic comfort in Esports venues, thus creating a guide that can assist in preparing tailored-suited designs to enhance the immersive experience of players, staff, and spectators.
The acoustic environment in indoor sports venues is complex due to various sound sources and factors like volume, surface materials, and space geometry [7].Gyms have hard surfaces that result in sound reflection, while sporting venues have predominantly soft equipment that lessens reflection.Regulations for reverberation time in sports facilities vary by country and are often based on factors like capacity, floor space, and ceiling height [8].Reverberation duration is not always a suitable criterion for assessing the acoustic environment, and the STI may be a better method.An example of a newly constructed athletics hall showed a higher reverberation duration than the Dutch government's standard [9].They argue that STI is a better method for assessing the acoustical environment in a sports venue as an example in the article, with a measured reverberation duration of 2.3 seconds, which was higher than the Dutch government's standard of 1.8 seconds.
In conclusion, the study of acoustic comfort in indoor arenas for Esports events is crucial to ensure an immersive and satisfactory experience for players, coaches, and spectators.This research aims to provide a conceptual framework that can assist designers and architects in preparing estimates of acoustic conditions and corrective activities in Esports venues.There is a significant relationship between the acoustical elements inside the space which determines the comfort value of the users and also the occupants [10].The framework will be based on critical literature studies and explore the differences in Esports venue design and the determining factors that influence human acoustic comfort.

Methodology
A total of more than 100 articles were found in multidisciplinary journals on applied acoustics, architecture and education, occupational and environmental sciences, as well as science and technology, that contained the research keywords "sports venue," "indoor sports," acoustic comfort," "factors," and "perceived environment."Furthermore, the original number of articles obtained was enlarged through a manual search of the reference lists of these papers to strengthen the reliability of the selected publications.Within the publication where the initial article was published, a library search was conducted using comparable terms.Noise levels and acoustic comfort and sporting facilities are regarded as the most important variables.The complete approach for generating the database for these determining factors is presented in Figure 2 flowcharts.However, after preliminary screening, only 54 articles are selected for the first screening which is close to the topic of research.
Nine articles were removed and examined for duplication and irrelevant titles during the initial screening, as shown in Figure 2.These five publications were found to be unrelated to the acceptable areas of research, which included an open-air stadium and a noise and volume study that had no relation with any sports enclosed facilities and venue.These irrelevant titles were eliminated from the initial screening.Six of the articles that were assessed based on their titles and abstracts were eliminated during the initial review.These abstracts were carefully studied to identify the scope of each study, research methodology, and conclusion.However, because not all the abstracts included the research methodology used, 39 publications were chosen for further in-depth examinations of their content and effects.During the second round of evaluation, one sample was deleted owing to irrelevant results.All 38 papers were carefully gathered and thoroughly studied in order to compile their important conclusions, which were then utilized in this research.It was discovered that most of them reported on more than one discovery.In terms of their scopes of study, technique employed, and outcomes, 25 of these findings were considerably matched as objective criteria with the issues of noise, acoustic comfort, and sports facilities requirements.Objective criteria are based on acoustic measurements and play a significant part in the architectural design process [11].On the other hand, the remaining 13 findings were categorised as subjective criteria for the acoustical comfort of athletic venue and were connected to players' satisfaction, coaches' contentment, and spectators' pleasure.Subjective criteria are based on the judgments of players and the spectators which are crucial in determining a space's acoustic qualities.
The research approaches employed in these studies were more diverse.Despite these variances, it is important to highlight that these findings are strongly linked to the subjects of perceived acoustic and acoustical comfort for athletic facility occupants.The title, abstracts, and full text of chosen journal articles from domains relating to the investigated issue were evaluated as part of the research process for this study.These English-language papers were gathered mainly from SCOPUS, ScienceDirect, Taylor & Francis Online, Science Gate, Research Gate, and Google Scholar to cover a wide range of topics.The evolution frequency of six deciding criteria may be seen in Figure 3 below, which shows the findings from previous research on the acoustic comfort of indoor venues.Due to the scarcity of studies on the subject, knowledge of acoustic comfort in indoor sports venues is still poor, as seen in the graph below.

The determining factors
For a long time, researchers have studied the perception of sound and noise, and the results demonstrate how people perceive sound comfort and the elements that influence it.The necessity for acoustic comfort in sporting facilities arises from the fact that poor acoustic settings combined with high noise levels in indoor sports facilities can cause discomfort and misunderstanding among participants.Regardless, some noise is a pleasant sound that may be used to increase participants' morale and performance during a game or activity.The main aims of these studies are to first understand the deciding elements and then transform the acoustical comfort into a nice sound for the players and spectators.Four major aspects have been identified as influencing the perception of sound and loudness in terms of the acoustic comfort of sporting venues: the constant noise source, the volume and the area of the space, the type (typologies) of the sporting facilities, the sound materials, and its characteristics.(Figure 4).
Based on the identified findings carried out and on theoretical analyses, it has been found that the following factors affect the acoustic properties can be classified in two main categories.

Architectural Factors
3.1.1.Volume and area of spaces.In all locations, especially sporting venues, volume has a substantial impact on reverberation time.Excessive volume has a negative influence on both spoken and musical sound reception.Because a sporting facility has a huge volume with a small seating area, the reverberation period is usually extremely long, and the space is regularly used as a multi-purpose hall, providing appropriate acoustics is usually challenging.Furthermore, the installation of an improperly built electric sound system exacerbates the situation, as the overlapping impact of delayed sound from spread loudspeakers can significantly reduce speech intelligibility [12].That is why this architectural parameter should be taken into consideration in the assessment of acoustic quality of sporting arena [11].This has a significant impact on the acoustics of sporting facilities, as most designers overlook the criteria of acoustical considerations while constructing them, resulting in unsatisfactory acoustic comfort for spectators and participants.
The acoustic conditions in a specific indoor sports venue are largely determined by the design of the ceiling in the sports arena.When choosing a ceiling shape, elliptical, semi-circular, and rounded shapes should be avoided at all costs.It is suggested that one seek for a solution in which sound is dispersed (trusses, irregularly shaped objects etc.)As a result, the form of a sports space's cross-section has a major impact on the space's acoustic qualities.When deciding on the shape of a lengthy space, the goal should be to make it as rectangular as possible.Above all, smooth, parallel walls must be avoided, as they contribute to the unpleasant flutter echo, obstructing communication greatly (both direct and through the public address system).As noted in the previous elements, it is recommended to use solutions that scatter sound, such as spectator seats, indoor climbing walls, and climbing frames.
Based on a case study conducted by Miji et.al [13], The Belgrade Arena's acoustic design, the usual absorptive material consisting of rock wool was put to the hall ceiling.The 2.5 cm thick slabs of this material, with a density of roughly 100 kg/m3, are suspended around 40 cm below the metal roof cover.Because of the metal roof's absorption coefficient, this absorptive treatment has high absorption over a wide frequency range.The principal absorptive surface in the hall is the ceiling treatment, which covers more than 7.500 m2.After this intervention, the main roof structure, a concrete grid, remained visible in the hall, allowing for further diffusing at the ceiling surface.As a result, the potential of intervention on the ceiling area of indoor athletic facilities to improve acoustical comfort in the arena are clearly demonstrated.

Type of hall and activities.
Different hall or arena typologies yield different acoustical consequences and require different design standards.Hall typologies are strongly linked to the activities and number of persons who took part.As a result of these elements, different guidelines for creating specific sports stadiums that are specifically created for specific sports and activities are established.Basketball courts, for example, have different acoustical considerations than other sports.The sound of the ball bouncing, the sound of people jumping, the sound of players moving around on the floor, and the shouting of the audience all mash up together to create a different ambiance than other typologies.
Meanwhile, Pekala and Lesna [14] studied the acoustic environment and noise exposure in 16 school gymnasiums in Poland.Variable sound levels were recorded during various activities, including warmups without balls (50-80 dB(A)), workouts with a couple of balls (55-90 dB(A)), volleyball, basketball, and football matches (77-93 dB(A)), and sports, games, and gymnastics (70-90 dB(A)).As a result, hall typologies and activities are a contributing aspect in the occupants' acoustical comfort.It does not affect much in the circumstances of halls created specifically for that particular activity, such as swimming pools for swimmers, unless the residents and spectators noise exceed the amount of absorptive material possible of the arena.Certain activities in a gymnasium or multipurpose hall may cause discomfort for spectators and other nearby persons who are participating in classes or other sports activities [15][16].
At Arrowhead Stadium on September 29, 2014, decibel levels reached 142.2 during an NFL game between the Kansas City Chiefs and the New England Patriots, shattering the previous record of 137.6 set in December 2013 during a game between the Seattle Seahawks and the New Orleans Saints in the National Football League.Coaches in Arrowhead reported feeling the earth shake and hearing ringing in the uncovered ear of their headsets [17][18].Recent Americans with Disabilities Act judgments require stadiums and arenas to provide closed captions for the hearing impaired since music and sound have become such a vital part of the fan experience.This necessitates the placement of text from the music or PA announcements on the scoreboards [19].However, not all sports noises are pleasurable.Fans who detest or are sensitive to excessive noise may have a poor experience.
In the cases of Esports activities in indoors venue, the acoustics control is significant to provide equal comfort between the players, and the spectators.For the players need to listen and communicate within their game and at the same time received the energy of cheering from the fans to motivate in game morals.This thin line is achievable with such design is proposed built for specific types of events and activities.

Sound materials and characteristics.
The acoustic quality of an indoor sporting area is heavily influenced by the presence of sound absorbent objects.Reduced reverberation time (and consequently reverberant noise) and lower interfering noise levels are two benefits of such objects.The percentage coverage of the ceiling and walls with sound-absorbing material of the highest class -A (materials with a sound absorption coefficient αw ≥ 0.9) should be used as a measure of such quality.If sound-absorbing materials of a lower class (B-E or unclassified products) are utilized, the number of marks for a specific partial index will be reduced [11].
Sport activities, according to Maffei et.al. [20], can be highly noisy (ball rebounds, calls, cries, runs, etc.) and several classes (students) can participate at the same time.Sport activities (rebounds of balls, calls, screams, runs, etc.) can be highly noisy, and many classes (students) can execute their sport activities at the same time.Thus, this factor is very crucial in determining the direction for this framework and architects and designers' consideration on applying correct absorptive materials for the sporting arena.The inclusion of sound scattering devices (trusses, field divider curtains, etc.) in sports venues allows the space to be subdivided, resulting in the transformation of the non-diffuse sound fields typical of sports spaces into diffuse sound fields.It should be recognized, however, that in this scenario, an unpleasant acoustic coupling will be produced between the smaller rooms, i.e., poor acoustic conditions in one of the spaces will likely have a detrimental impact on the adjacent areas.In the case of sports halls divided into three sections by partition curtains, a sound absorption partition curtain should be utilized in any circumstance.It should be used in conjunction with a 2 m high highly absorbing impact protection wall and an absorbing ceiling [21].Based on report by Moritz et al. [21], investigations into the sound insulation of sports hall partition curtains revealed ways for improving the sound insulation of such installations in situ.The partition curtains should also be able to absorb sound.A proposal was made within the project on how modern divider curtains may be manufactured to serve both capabilities.

Presence of Constant Noise
Source.Individual perceptions of the noise level of an indoor area, such as a sporting facility, are influenced not only by the amount of noise made by the inhabitants within the space and the source of the noise, but also by the sporting facility's surrounding environments or external noise.Additionally, the noise of the audience and spectators inside the sporting venue is more focused on the aspects affecting acoustic comfort for this discussion.
The author of this paper argues it would be hypocritical to ignore the excessive noise caused by fans inside and outside the sports arena due to their passionate demonstrations of enthusiasm during sporting events.Because the game is played live, the crowd's passion, love, excitement, and disappointment are all shown in a raw and immediate manner, which is why racial epithets are so popular during live games [22].However, there is an ongoing trend of fans making noise outside the sporting arena even after the games have ended, causing acoustic discomfort to those living nearby, as well as players and spectators.The noise generated by the crowds, on the other hand, can be used to increase the players' motivation and performance throughout their games.As a result, such good sound enhances the sporting experience for all other participants and spectators in the arena.This classification will be elaborated further to understand the importance of each determining criteria and how impactful of each into architectural consideration towards indoor sporting facilities spaces.

Discussions
Acoustic comfort encompasses a wide range of factors as shown in conceptual framework in Figure 5.The findings and suggestions in this study are based on prior studies and are unique to different sporting venues.The majority of the articles in this report were sourced from a prominent English-language journal database.When the findings from these renowned databases were examined, they revealed a wide range of tenant traits and behaviours (activities involved, number of peoples and behaviours in the arena), the characteristics of the typical sports facilities (the volumes, architecture elements, ceiling height, form) and noise sources in terms of noise and acoustic comfort perceptions during a sports activity as well as the typologies of the facilities.In particular, the noise generated from specific activities of the occupants as well as high number of participants and poor absorptive materials towards the sporting facilities appear to be the most influential factors in perceived the acoustic comfort.
The noise by spectators' and crowds' cheers and shouting of the sporting facilities and internal noises (such as the sports equipment's itself, machine-related noise, and external neighbourhood noise) can (and does) influence the occupant's acoustical comfort and perceptions of noise.Additionally, the physical environment characteristic of the sporting facilities such as the volumes, architectural elements, and ceiling height affect the occupant's acoustical comfort however, these factors are not as important as the noise sources and the density of the occupants.
Thus, considering all these factors, in the case of Esports venue, the criteria need the additional measure for the players competing.Loud noises could harm the players and lead to certain disadvantages in the game or in long term run.The venue will be full of sounds from the game and the cheers and jeers of the crowds.Thus, the application of soundproof booths or a good noise absorbent could be part of the solutions.Even though the existence of the noise cancelling microphone is popular, it still does not provide the very best acoustic comfort for the players.

Conclusions
In this study, 38 publications were studied to build an acoustic comfort framework in sporting venue for Esports.The output was a viable tool for measuring the acoustic comfort of Esports venues based on the four specified deciding parameters.By employing the literature review's independent variables and characteristics as deciding factors, this study adds to the current body of knowledge about the various acoustic comfort classes.For the purposes of defining the optimum acoustical comfort of Esports venue, on-site psychological and physical tests should be conducted.To conclude, based on these studies and outcomes, the architectural design for Esports venue with the consideration of acoustical design should prioritize which determining factors contribute most to the acoustical comfort of occupants in sporting facilities.

Figure 1 .
Figure 1.The relation between the subjective criteria and the objective criteria and linkage between the spectator and players acoustical comfort based in the determining factors of indoor arena.

Figure 2 .
Figure 2. The screening and review procedure for identifying suitable sample articles is depicted in this flowchart.

Figure 3 .
Figure 3.The determinant factors found from 38 articles.

Figure 4 .
Figure 4.The frequency of the outcomes reported in the 38 papers was used to propose determining factors.

Figure 5 .
Figure 5.The proposed acoustic comfort conceptual framework classification in an indoor arena venue.
Physical education (PE) teachers or coaches are compelled to communicate with gymnasium and swimming pool users by blowing whistles due to limited voice intelligibility which contributes to another factor which is the constant noise sources.