The articulation between the STS Approach and Environmental Education for the contextualization of Acoustics in Physics Teaching

Noise pollution presents itself in an invisible, dangerous, and permanent way, with long-lasting consequences. Acoustic discomfort within the school environment affects not only human health but also the quality of verbal communication and student performance. An appropriate acoustic environment contributes to the improvement of the teaching and learning process in addition to enhancing the interpersonal relationships involved in the educational process. Moreover, it is important to introduce acoustics-related subjects, such as environmental noise, into high school science and physics syllabi. As urban noise is a global concern and scope, students may face the need to make decisions related to environmental practices in their future lives, such as those concerning comfortable sound levels. Articulating the STS Approach with Environmental Education, we seek to combine the interdisciplinary content of Acoustics with an environmental awareness that goes beyond mere conservationist reductionism. In addition to the mandatory curricular knowledge, STS Education adopts a scientific and technological education based on a social construction that is culturally and socially contextualized.


Introduction
High sound pressure levels are closely related to multiple negative effects on public health, apart from being a risk factor for various diseases.Noise pollution presents itself in an invisible, dangerous, and permanent way, with long-term effects that go beyond hearing losses -other chronic physiological and psychological effects, such as cardiovascular disorders and burnout syndrome, are impacted by exposure to high levels of sound pressure (Zilio, 2012).That is why effective and continuous environmental noise control is of extreme importance in the prevention of the harmful effects it can cause on the health of all individuals.Far beyond mere hearing discomforts, the prevention of noise pollution concerns health and quality of life.
According to the World Health Organization (WHO), excessive noise seriously harms human health and interferes with daily and ordinary activities.According to the entity, noise pollution occupies the second place as the highest cause of diseases, behind only to air pollution.Nowadays, it is estimated that around 5% of the global population has some kind of disabling hearing difficulties.The projection is that by 2050, 25% of the world's population will be living with some degree of hearing difficulties and/or losses (WHO, 2019).
Urban noise is a global issue, and its relationship with quality of life and human health has been extensively addressed in academic papers (Popescu et al, 2010;Stansfeld et al, 2011; Urban and Maica, 2013).The urbanization process of the city of Rio de Janeiro, Brazil, was strongly influenced by the aspects of urban mobility.The movement around the "highway system ideology" throughout the 20 th century in Brazil resulted in expressways, tunnels, and viaducts built in a process, usually merely focused on roads for any kind of transportation and mobility solutions within the cities, that became decisive for the expansion of the city towards its suburbs (Torres, 2018).Due to this ideology that permeated the public policies of Brazilian municipalities for decades on end, it is not uncommon to see a school building right next to the main urban roads of Brazilian cities (Figure 1).The implementation of transport infrastructure in urban contexts is often associated with environmental problems, whether due to visual blockage, sunlight interference, ventilation, and changes to the urban microclimate.However, it is mainly due to the emission of noise and pollutants by motor vehicles (Cirino, 2012).
Acoustic discomfort within the school environment affects not only human health but also the quality of verbal communication and student performance, interfering with concentration, writing and speech development, as well as learning and reading comprehension (Dreossi, 2004).The appropriate acoustic environment contributes to the improvement of the teaching and learning process in addition to enhancing the interpersonal relationships involved in the educational process (Oiticica and Gomes, 2004).The acoustic conditions of schools must guarantee that the educational activities can be carried out within proper setups, without any discomfort due to external and/or internal noise.
Hence, it is important to introduce acoustics-related subjects, such as environmental noise, into high school Science and Physics syllabi as well.In order to place science and technology in concepts linked to the social and environmental context that surrounds the students, preparing them for a balanced and responsible life in society, we seek to combine the Science, Technology and Society (STS) Approach with Environmental Education, intending to develop didactic sequences that combine the interdisciplinary content of Acoustics with an environmental awareness that goes beyond mere conservationist reductionism.
The understanding and transformation of the current reality, as predicted by Paulo Freire (1987), requires the understanding of science, technology, society, and nature within a totalizing environmental context, as these dimensions are intrinsically complementary.
Thus, the articulation between the fields of the STS Approach and Environmental Education can be an important strategy in the struggle to overcome the supposed contradiction in the discourses on environmental conservation and scientific, technological, and economic developments, especially those that entirely undermine human formation and that are linked to merely utilitarian projects (Luz et al, 2020).

Noise in School Environment
School buildings must provide proper environmental settings for different climatic conditions, such as temperature, wind, and humidity, not to mention ideal conditions of vision and lighting, whether natural or artificial.The buildings must also guarantee the best acoustic quality, with protection against intrusive noise, providing good intelligibility between teachers and students, as well as protection against air pollution, health, and hygiene (Hagen et al, 2002).
Additionally, their facilities must be within acceptable levels of noise.The main activity developed is teaching and learning in different age groups and fields of knowledge.Therefore, the need for satisfactory acoustic conditions in which the student can be encouraged to learn is evident, with the acoustic-architectural space being fundamental for such conditions (Kowaltowski, 2011).
In the specific case of Brazilian school buildings, architects and engineers are very rarely concerned with acoustic quality despite its fundamental importance (Kowaltowski, 2011).Therefore, it is quite common for such buildings to be unproperly built in terms of intrusive noise protection, leading to more complex solutions and subsequent corrective actions that are usually higher in cost (Seep et al, 2000).
There is a widespread neglect of this merit in Brazilian school buildings, and a very well-known negative case happened in the state of Rio de Janeiro, during the late 1980s: it was how the Integrated Centers of Public Education (CIEPs1 ) were designed and built, with classrooms with "half walls" facing the central hallways (Figure 2).Classrooms were open to each other, so any sound produced within a given classroom would have no barrier whatsoever, causing a generalized production of internal noise in the whole school environment (Castro, 2009).Corrective actions had to be taken after the constructions, closing the walls between the classrooms so that the problem could be mitigated (Azevedo, 2007).The CIEP "half walls" was an emblematic case of how high noise levels and/or inadequate reverberation conditions are harmful to the learning process, contributing to a low overall performance of the educational process.
Researchers have shown the influence of acoustics on student learning and performance, as well as on social behavior and speech comprehension (Bradley, 1986;Seep et al, 2000;Hodgson and Nosal, 2002).Unfavorable acoustic conditions make learning and teaching unnecessarily exhausting (Hagen et al, 2002).Exposure to high sound levels causes greater fragility in the auditory system of the exposed individual, so the daily class time added to the hours worked in extracurricular activities in schools contributes to worsening the problem (Moraes et al, 2013).
Among those involved, students are certainly the most affected, as unsatisfactory acoustic conditions strongly impact the quality of learning.According to Dreossi (2004), acoustic aspects are of extreme importance to students' academic performance.Regarding the teachers, the failure to meet proper criteria for acoustic comfort leads to excessive vocal effort -even though there are no guarantees that higher speech intelligibility can be reached with a higher vocalization volume.Consequently, teachers become victims of spaces that are inadequate for the performance of their professional activities (Seep at al, 2000).With their occupational hygiene compromised by the exposure to this physical agent of noise, teachers can become susceptible to illnesses caused by stress, sleep disorders and irritability, as well as vocal and hearing conditions, which are damaging to their health and contribute to absences, sick leaves, and could even lead to the renouncing of the profession.Working and/or studying in an acoustically comfortable environment not only increases well-being at a personal level, but also labor satisfaction and, therefore, productivity and learning (Picard and Bradley, 2001).
The quality of education also depends on a teaching environment to which external components contribute harmoniously to deepen and expand student learning (Karabiber and Celik, 2002).Thus, school architecture plays a key role, as the actual spatial area of classrooms is intrinsically related to the teaching methodology (Kowaltowski, 2011).Problems with the acoustics of the school environment can create an atmosphere that lacks discipline and effective communication between students and teachers.
The acoustic conditions of the outdoor environment can influence, in a positive or negative manner, the sound quality in closed educational spaces (such as classrooms) and/or opened ones (such as courtyards).Therefore, outdoor environments with acoustic attributes that favor a sound ambience that provides cognition of teaching and learning activities should be promoted (Paixão, 1998).The physical characteristics and acceptable acoustic requirements of the different types of environments of a building used for educational purposes require attention, and should promote privacy, sound insulation and the proper conditioning for carrying out educational activities (Seep et al, 2000).
In this sense, it is also important to include the issues associated with Acoustics and environmental noise into the Physics syllabus taught to high school students.Science teaching allows working on the relevance of the contents that need to be addressed, relating them to social-environmental issues or even to cultural values and habits (Moraes, 2006), bringing awareness and fully expanding the potential of life in society and the relationship of the community with the surrounding environment.

STS Approach and Environment Education: contextualizing Acoustics
The Brazilian Common National Base Curriculum (BNCC 2 ) emphasizes the importance of discussing the role that scientific and technological knowledge (and advances) play on environmental issues within the context of Science Teaching to minimize human impact and improve living conditions at local, regional, and global levels: "The social, historical and cultural contextualization of science and technology is fundamental for them to be understood as human and social undertakings [...] it is also proposed to discuss the role of scientific and technological knowledge in social organization, in environmental issues, in human health and cultural formation, that is, analyzing the relationships between science, technology, society and the environment."(Brazil 3 , 2018)   In addition to the mandatory curricular knowledge, STS Education takes on a scientific and technological education based on a kind of social construction that is culturally and socially contextualized.It encompasses science, technology, and the teaching of these subjects as a way to influence the daily lives of students, developing skills such as the ability to analyze problematic situations while seeking possible solutions in a grounded and responsible manner (Santos and Mortimer, 2002).As urban noise is a global concern, students may face the need to make decisions related to environmental practices in their future lives, such as those concerning comfortable sound levels.
The STS Approach in Basic Education aims to promote the scientific education of citizens, with the acquisition of knowledge, skills, and values for life in society, providing students with a critical reading of the world, enabling their participation and the consequent democratization of decisions in social issues involving Science and Technology (Auler et al, 2009).In this perspective, it is important to unveil the myths that cross the environmental and scientific-technological practices of the theme to avoid reductionist attitudes by the students in dealing with current socio-environmental discussions.
In this manner, STS Education contradicts a type of science teaching that endorses a traditional perspective, one that is linked to a kind of environmental education based on a conservative matrix, which is often limited to some sporadic appendix of science classes, focusing solely on the behavioral issues of individuals or official commemorative dates, with the environment understood only and merely as nature to be preserved from human action, maintaining an uncritical superficiality about a structurally conflicted and complex reality, whose contradictions do not enter science classrooms (Loureiro and Lima, 2009).
In the case of Acoustics, it is possible to articulate the mandatory curricular subject of Mechanical Waves in Physics classes with Environmental Education aimed at high school education, considering socio-environmental issues that derive from environmental noise, its risks and impacts on public health, as well as the need to develop social participation in matters that concern such socio-environmental issues.
The proposed topics could range from asking students to measure the noise levels of their everyday environments using free sound pressure level (SPL) meter apps from their smartphones (Figure 3) to having them transform their classrooms into more acoustically comfortable environments, in addition to capturing and recording the sounds and noises that surround them, among other possibilities.
A pilot project is currently being implemented at a public high school in a low-income neighborhood of the city of Rio de Janeiro, Brazil: a didactic sequence in a Physics class composed of four different assignments, for students of the senior year.The first assignment was to use a free sound level meter smartphone application to measure environmental noise levels produced in their classes, school areas, homes, and neighborhoods.The students must take notes and write a journal about which places, days and hours are more acoustically uncomfortable for them and their families -they were encouraged to record those sounds (alongside some other ones they eventually found pleasant to hear) using their smartphones.It is important to emphasize that as a high school project, rather than the accuracy of the data collected, the focus was the awareness the project could raise about sound pollution, that is why professional sound pressure level meters were not required.After gathering the sounds recorded by the students, the teacher created a "sound library" and proposed the next assignment: students were called to use a free and open-source software designed to analyze the contents of audio files to have practical and visual contact with the sound parameters to which they were exposed, such as sound intensity and amplitude, frequency, and wavelengths.
The following assignment required students to use the noise level data previously measured to sketch rough noise maps of their neighborhood and school surroundings.In the same class, after visualizing their own noise maps and hearing some of their recorded sounds, students were invited to discuss what sound levels were suitable for the different environments: from family homes to rock concerts, shopping malls to workstations, classrooms to open streets -presenting them with article excerpts that discuss the health risks due to long exposure to inappropriate sound levels.
The last assignment of the didactic sequence required students to create a kind of sound level meter using Arduino (an open-source electronic platform), in a matter that it could be placed in the school's main hallway so that all students, teachers, and employees could observe the noise level generated from inside the institution.The students would assemble an analog VU meter, capable of measuring sound intensity, using a sound sensor module that transforms any sound variation from the environment into signals that were received, read, and processed on the Arduino, which then controlled a set of LEDs that were turned on or off based on the sound intensities received from the environment.
In this way, the contents covered should be sound pressure and SPL, sound intensity and power, acoustic energy, sound frequencies and wavelengths, sound speed, sound perception, public and occupational health and environmental noise in the students' communities.It is important to state that a detailed description of the project itself for teaching acoustics and sound pollution at high school level Physics, the assignments presented in this didactic sequence, and the consequent analysis of the data obtained from its application with the students will be the subject of future works.
In addition to the knowledge that is acquired, the STS Approach can help students develop useful skills for their daily lives.This includes the ability to analyze problematic situations seeking possible solutions in a responsible way, so in the future, when faced with tough decisions related to best environmental practices, such as complying with sound levels comfortable for a life in society, they will be able to propose actions to minimize the corresponding impacts.

Final Considerations
The overcoming of socio-environmental contradictions, caused specifically by the disorderly development of large cities regardless of their inhabitants, is directly related to the worsening of environmental problems and the lack of social well-being promotion.
Environmental degradation is an increasingly present concern throughout the globe, and it is a reality that needs to be changed and surpassed.This implies an urgent shift in basic education to provide guidance to the citizens who will soon need to maintain the best social-environmental conditions for human existence within their communities as well as on the planet as a whole.
When considering Science Teaching in articulation with Environmental Education, the relevance of emphasizing the importance of proposals that enable change is perceived.After all, the objective of education should be to help raise analytical, inquisitive and thoughtful individuals who can contribute to a positive change in values and attitudes that will create ecologically perceptive citizens, capable of identifying and problematizing socio-environmental issues and acting on them.
Thus, the articulation between the fields of the STS Movement and Environmental Education can be an important strategy to overcome the supposed contradiction in the discourses on environmental conservation and scientific-technological development, especially those that undermine human formation in its entirety and that are linked to mere utilitarian projects.Science, technology, society, and the environment need to be seen as one so that the current reality of a global socioenvironmental warning can be understood and transformed.After all, these dimensions are intrinsically complementary.

Figure 1 .
Figure 1.A Brazilian public school right next to a major urban road in the city of Rio de Janeiro, Brazil.

Figure 2 .
Figure 2. Examples of "half walls" in the classrooms of two different CIEPs.They contributed to a generalized production of internal noise in the schools' environments.In the pictures, yellow arrows point to the gaps between the actual walls of each classroom and the hallway ceiling.The faces of teachers and students were blurred for confidentiality purposes.

Figure 3 .
Figure 3. Students can use free sound level meter apps from their smartphones to measure environmental noise levels.