Introduction

A soundscape refers to the collection of sounds that can be heard in a specific location or environment. These sounds can originate from natural sources (like animals, wind, or water) or from human-made sources (such as vehicles, machines, conversations, or music). The concept emphasizes the importance of our sonic environment and how it influences our experiences, perceptions, and feelings towards a particular place or setting.

Soundscape: the concept

The concept of "soundscapes" was popularized by the Canadian composer and environmental sound researcher, R. Murray Schafer.

During the 1970s and 1980s, Schafer conducted studies through his World Soundscape Project (WSP) that focused on changes in the acoustic environment. He and his team recorded sounds from various settings and analyzed their effects on both people and the environment.

In the 1990s, the idea of soundscapes gained recognition and further exploration in academic circles, with a focus frequently on acoustic ecology and sound composition.

Different categories of sounds in Soundscapes

Sounds in the concept of Soundscape can be divided into 3 categories: Keynote Sounds, Signals and Soundmarks.

• 🚙 Keynote Sounds:

These are the background sounds within an environment that are often so familiar or constant that they might go unnoticed by the individuals in that setting. They're the pervasive, frequently overlooked noises that set the tonal backdrop of an area. For instance, in an urban environment, this might be the distant hum of traffic or the sound of air conditioning units.

• 🔔Signals:

These are sounds distinct from the keynote sounds and are intended to be consciously heard. They command attention and often convey specific information. An example is the sound of a church bell. This sound signifies a specific time, calls for prayer, or announces particular occasions.

• 🎙️ Soundmarks:

This term represents the auditory equivalent of a landmark. A soundmark is a sound or sonic experience characteristic of a specific location or community. It's so distinct and unique that it can identify the place and often carries emotional or cultural significance for the people residing there. For example, the distinct sound of a marketplace or a particular animal in a region can be considered a soundmark.

Hi-Fi and Lo-Fi Soundscapes

In the context of R. Murray Schafer's Soundscape theory, "Lo-Fi" and "Hi-Fi" describe the quality of the acoustic environment.

• 📀 Hi-Fi (High Fidelity) Soundscapes: Refers to soundscapes where individual sounds can be clearly distinguished due to minimal background noise. An example is a quiet countryside where one can separately hear birds chirping, wind rustling, and a stream flowing. In such environments, even distant soft sounds can be discerned.

• 💿 Lo-Fi (Low Fidelity) Soundscapes: Denotes soundscapes where sounds blend into a generalized noise. An example is a busy city center where traffic, crowds, and urban sounds merge into a constant background hum, making it challenging to identify individual sounds.

Schafer contended that many modern urban areas are becoming "Lo-Fi", deteriorating their acoustic quality. He emphasized the significance of preserving and creating "Hi-Fi" soundscapes for human well-being and a vibrant acoustic environment.

ISO Standards

The International Organization for Standardization (ISO) has defined "Soundscape": acoustic environment as perceived, understood, and interpreted by humans in context. The emphasis is on human subjective perception and interpretation of sounds in their surroundings.

The ISO 12913 series comprises:

• ISO 12913-1: Ensures clear and consistent use of "Soundscape" and related terms.

• ISO 12913-2: Focuses on measuring soundscapes, including data collection.

• ISO 12913-3: Addresses data analysis, specifically the analysis of soundscape data.

Collectively, these standards provide a framework for capturing, analyzing, and evaluating soundscapes, offering a standardized method to understand and quantify the acoustic environment regarding human experience. These standards aim to describe and evaluate soundscapes beyond mere noise monitoring, integrating cultural, social, and personal aspects into a standardized assessment.

Analyzing Soundscapes

A Soundscape Investigation (SC-Investigation) seeks to capture and analyze the acoustic environment in relation to human experience, going beyond simple sound level measurements to consider perceptions, meanings, and emotions connected to sounds in the environment.

Key elements of a typical SC-Investigation are:

• Purpose & Context: Define the study's goal and the specific environment or community being examined.

• Field Studies & Data Collection: Acoustic measurements - Recording sounds in the chosen environment.

• Context data: Information about the physical surroundings, time, weather, etc.

• Participant Survey: Capture human perceptions and evaluations, including volume, annoyance, preferences, emotional responses, and cultural meanings.

• Analysis & Interpretation:

  • Quantitative: Analyze sound levels, frequency spectra, etc.

  • Qualitative: Interpret data from interviews/questionnaires on perceptions.

• Identification of Keynote Sounds, Signals, and Soundmarks: Determine characteristic and significant sounds based on data and analysis.

• Reporting & Recommendations: Summarize findings and provide suggestions, such as noise reduction or preserving certain soundmarks.

• Stakeholder Engagement: Involve the community or other stakeholders to ensure their perspectives and concerns are addressed.

In essence, an SC-Investigation ensures not only the capture of technical and acoustic data but also a deep understanding of human experiences and perceptions of sounds, enabling informed decisions to enhance or preserve acoustic environments.In Soundscape (SC) research, as per R. Murray Schafer, there are three crucial facets to consider in a Soundscape Investigation:

✅ Sound: Refers to the objective acoustic features of the environment, such as type, source, volume, duration, and frequency. This includes technical sound analyses.

✅ Context: Pertains to the circumstances surrounding the sounds, including the physical environment, time of day, season, socio-cultural conditions, etc., influencing the perception and significance of sounds.

✅ Perception: Addresses the subjective human experience and interpretation of sounds, capturing feelings and evaluations.

Together, these elements provide a comprehensive framework for understanding soundscapes, emphasizing both objective and subjective dimensions of the acoustic setting. It's vital to integrate all three aspects for a complete picture of the acoustic environment and its human significance.

The perception of Soundscapes

The perception of soundscapes is influenced by various factors that shape the overall experience:

• Context: This determines how sounds are perceived and interpreted, influenced by factors like physical environment, time of day, cultural or social norms, and current activities. For instance, a sound in a forest may be perceived differently than in an urban setting.

• Sound Sources: These are the specific objects or events producing sound, ranging from natural sources like birds or wind, to man-made sources such as traffic or industrial noises.

• Acoustic Environment: Refers to the objective acoustic characteristics of a location, including its echo, sound absorption, and reflection. These aspects influence how sounds are heard and how they propagate in space.

• Auditory Perception: Relates to the physiological manner in which the ear perceives sounds, influenced by factors like age, hearing impairment, and other physical attributes of the listener.

• Interpretation: Once a sound is perceived, the brain interprets its meaning, influenced by personal experiences, cultural background, and listener's expectations.

• Reactions: These are immediate emotional, physical, or psychological responses to sounds. For example, a sudden loud noise might trigger a startle response, while gentle wave sounds can be soothing.

• Consequences: These are the long-term effects of sounds on an individual, which can be positive (like relaxation from calming music) or negative (like stress or insomnia due to persistent noise).

These factors are interconnected and influence each other, providing a comprehensive framework for understanding how people experience and respond to their acoustic environment.

Soundscape Research

In soundscape research, various methods are used to capture both the objective sound characteristics of an environment and the subjective perception and evaluation by humans. Commonly used methods include:

• Surveys:

  • Likert Scale: Participants indicate their agreement or disagreement with specific statements on a scale, e.g., from "strongly agree" to "strongly disagree".

  • Open-ended Questions: Allow participants to respond in their own words, providing detailed and nuanced information.

• Dummy Head Recordings: This technique captures sounds as they would be perceived by the human ear. A dummy head equipped with microphones in its ears records a three-dimensional representation of the acoustic environment.

• Binaural Measurements: Similar to dummy head recordings, but often with two microphones either on a person's ears or a dummy head. This captures sounds as perceived by both ears, resulting in a spatial and immersive recording.

• Observation Methodology: This can include both direct and covert observations of individuals in a particular acoustic environment to observe their reactions to various sounds. It might also involve noting behavioral reactions, movements, and interactions concerning the acoustic surroundings.

• Soundwalks: Here, groups are guided through an environment and asked to focus on the surrounding sounds. They can later discuss or record their perceptions and reactions.

• Acoustic Mapping: Visualizes acoustic data over a specific region or location, which can help identify noise sources, quiet areas, or other acoustic features.

• Diaries or Audio Journals: Participants may be asked to record their daily acoustic experiences, reactions, and thoughts over a specified period.

The choice of methods depends on the specific goals of the soundscape research. Often, multiple methods are combined to get a comprehensive picture of the acoustic environment and human responses to it.

Dimensions of ambient noise

When assessing ambient noise, humans consider various perceptual dimensions. These dimensions capture different aspects of the acoustic experience. The provided dimensions "event-sparse-event-rich" and "annoying-pleasant" are commonly used in soundscape research. Here's a brief explanation of these and other potential dimensions:

• Event-Sparse - Event-Rich: This dimension refers to the density and diversity of acoustic events in an environment. An event-sparse setting might be a quiet rural area with occasional bird sounds, while an event-rich setting could be a bustling city street with constant varied noises.

• Annoying - Pleasant: This gauges the overall quality or evaluation of sound. While individual preferences can vary, certain noises like loud traffic are generally deemed annoying, whereas natural sounds like birdsong or trickling water are often described as pleasant.

Beyond these, there are additional potential perceptual dimensions explored in soundscape research:

• Familiar - Unfamiliar: Describes how recognizable or familiar a particular sound is to a listener.

• Natural - Artificial: Assesses whether a sound is perceived as of natural origin (e.g., wind or animal noises) or artificial (e.g., machinery, music, or man-made sounds).

• Static - Dynamic: Refers to whether the sound environment is constant or changing.

These dimensions can be evaluated using various methods, such as surveys, soundwalks, or observation methodology. Understanding these dimensions and how people rate them is vital for acoustically designing and enhancing an environment.

Soundscape analysis - statistical variables

In statistical analysis, particularly in structural equation modeling, two key terms are "manifest variables" and "latent variables". Here's a summary of their definitions and differences:

• Manifest Variables:

  • Directly measurable or observable.

  • Concrete indicators that can be recorded in a dataset.

  • Examples include a test score, a person's age, their income, or any other variable directly measured in a study.

  • Often termed "observed variables" as they can be directly observed and recorded.

• Latent Variables:

  • Not directly measurable or observable, representing abstract constructs.

  • Typically signify underlying ideas or concepts that can be indicated or measured by multiple manifest variables.

  • Examples are intelligence, satisfaction, depression, or motivation. Although we can't measure these concepts directly, they can be indicated through various tests, surveys, or scales that produce manifest variables.

To illustrate: Suppose you want to measure "life satisfaction" (a latent variable) in a study. Since you can't measure it directly, you use a survey with questions like "How satisfied are you with your overall life?", "How satisfied are you with your job?", and "How satisfied are you with your social relationships?". The responses to these questions are manifest variables, serving as indicators for the underlying concept of life satisfaction.

Informative Masking

It refers to the phenomenon where one sound or signal (the "signal") is overlaid or "masked" by another sound or signal (the "masking noise"), making the original signal less discernible or even imperceptible.

What's unique about "informative masking" is that the masking noise often contains relevant or important information for the listener. This means it's not just a disruptive noise covering the signal but one that is informative and contextually relevant.

A common example of masking is hearing a soft conversation in a noisy environment, like a busy café, where background noises can overshadow the desired conversation.

In "informative masking", an instance would be trying to follow a conversation in a group while another engaging conversation occurs nearby. The second conversation (the masking noise) is also informative, capturing your attention and possibly masking the initial conversation you intended to follow.

Understanding masking effects is crucial in acoustic research and especially in soundscape research. It helps in discerning how different sound sources in an environment interact and influence the perception and comprehension of information.

Restorative Environments

Theory of "restorative environments," developed notably by Rachel and Stephen Kaplan. This theory suggests that certain settings, especially natural ones, have the ability to reduce mental fatigue and boost cognitive functioning. There are four primary characteristics that define a restorative environment:

• Fascination: Refers to elements in the environment that effortlessly capture attention. Examples include natural phenomena like flowing water, birds, or swaying trees.

• Extent: The environment should be coherent and complete enough to engross an individual. It should possess a certain scale and depth, giving a feeling of being in a different world.

• Being Away: Refers to the sensation of being physically or psychologically detached from everyday surroundings or routines. A restorative environment offers a break from daily stresses and distractions.

• Compatibility: The environment should align with individual intentions and interests, catering to personal desires and needs, be it seeking tranquility, meditating, walking, or simply enjoying nature.

These characteristics have gained significance in environmental psychology and the design of recreational and green spaces. The presence of these elements in a setting can aid in diminishing cognitive fatigue and enhancing overall well-being.

Noise Control vs Soundscape

The traditional noise control understanding and the soundscape approach differ in their methodologies and focus on acoustic environments.

• Perception of Ambient Noise is Multidimensional:

  • 🔇Traditional Noise Control: Focuses mainly on objective noise measurements, especially sound levels and frequencies, aiming to minimize disruptive or harmful noises.

  • 🔊Soundscape Approach: Understands that human perception of sound is complex and multidimensional. It's not just about the volume but also about perception - whether a sound is seen as pleasant, disruptive, intriguing, or dull.

• The Same Sound Can Elicit Different Reactions in Different Contexts:

  • 🔇Traditional Noise Control: Often views noise in isolation and a standardized manner.

  • 🔊Soundscape Approach: Acknowledges the importance of context. For instance, children playing in a park might be perceived as pleasant, but in a library, it might be considered disruptive.

• Adding Sounds Can Enhance the Overall Acoustic Experience:

  • 🔇Traditional Noise Control: Primarily aims to reduce or eliminate noises.

  • 🔊Soundscape Approach: Recognizes that adding certain sounds, like the splash of water or birdsong, can enhance the perception of an acoustic environment and mask undesired noises. The goal isn't just noise reduction but creating a positive acoustic environment.

In summary, while traditional noise control typically takes a more technical and objective view, the soundscape approach offers a more comprehensive and subjective perspective on acoustic environments, emphasizing the significance of human experience and perception concerning soundscapes.

Community Tolerance Level (CTL)

The Community Tolerance Level (CTL) is a concept from noise research and regulation, referring to the threshold of ambient noise at which a community or population begins to perceive noise as disruptive or unacceptable. Key points about the Community Tolerance Level:

• Variability: Different communities have diverse tolerance levels, influenced by cultural, historical, demographic, or economic factors. For instance, an urban community might tolerate higher noise levels than one in a rural area.

• Adaptation: Over time, a community's noise tolerance can change, especially if noise levels increase gradually. This phenomenon is often termed "noise adaptation." However, adaptation doesn't necessarily equate to acceptance or satisfaction.

• Reference Levels: CTLs can serve as benchmarks for local or national noise regulations. If a community's average noise level exceeds the CTL, it might indicate a noise issue requiring attention.

• Community Involvement: Determining a specific community's CTL effectively often involves direct consultation with its residents, achieved through surveys, interviews, or public consultations.

• Additional Factors: Noise tolerance isn't solely about volume. Other factors, like the nature of the noise, time of day, duration, and predictability, can also influence perception and acceptance.

In summary, the CTL acknowledges the complexity of noise and its impacts on the community. Different communities have varying views on what's acceptable, emphasizing the need to consider each community's specific needs and preferences in noise regulation and management.

Soundscape maps and noise maps

Both of them visually represent acoustic information, but they differ in approach, focus, and purpose. Here are the main distinctions:

• Purpose and Perspective:

  • Noise Map: Primarily focuses on undesirable or harmful noises and their intensity. Its main aim is to identify noise problems and develop noise-reduction solutions.

  • Soundscape Map: Concentrates on the entire acoustic environment and how it's perceived by people, covering both positive and negative aspects. It provides a comprehensive picture of the sound environment and its effects on individuals.

• Data Source:

  • Noise Map: Typically utilizes objective measurement data gathered from sound level meters or computer models.

  • Soundscape Map: Can incorporate both objective measurement data and subjective data collected from surveys, interviews, and participatory methods.

• Dimension of Representation:

  • Noise Map: Generally represents only the sound pressure level.

  • Soundscape Map: Can depict multiple dimensions, including volume, sound quality, perception, and emotion.

• Evaluation:

  • Noise Map: Evaluation is usually based on established standards and thresholds.

  • Soundscape Map: Evaluation might be more subjective, considering aspects like sound quality, ambiance, and cultural significance.

• Applications:

  • Noise Map: Commonly used in environmental planning, noise control, and urban planning.

  • Soundscape Map: Used in similar areas as noise maps but can also be applied to sectors like tourism, cultural heritage, and community planning.

While both noise maps and soundscape maps are valuable tools for representing acoustic data, their methodologies and objectives differ. Noise maps often adopt a technical and problem-focused approach, whereas soundscape maps offer a more holistic, experience-based perspective.

Significance of Soundscape

The significance of the soundscape concept is anticipated to grow due to several reasons:

• Urbanization: As cities become more populated and dense, acoustic environments get more complex. There's an urgent need to understand and design these spaces to be pleasant for inhabitants.

• Advanced Measurement Tools: As mentioned, advanced technologies are now available for sound measurement and analysis. These tools allow for a deeper dive into the soundscape concept, understanding how different sounds interact.

• Rising Public Expectations: People are becoming more critical of their environments, with a growing awareness of noise's impact on well-being. They seek living spaces that are both visually and acoustically pleasing.

• Health Implications: An increasing number of studies highlight noise's health effects, ranging from sleep disturbances to heart conditions. The soundscape approach can mitigate these effects, considering not just sound levels but also the quality of the acoustic environment.

• Community Inclusion: The soundscape approach emphasizes community feedback in designing acoustic environments. With a growing interest in participatory planning, this aspect of soundscaping becomes more relevant.

• Emphasis on Positive Sounds: Rather than just focusing on eliminating unwanted noises, the soundscape approach promotes and emphasizes positive sounds, recognizing that not all sounds are harmful and some might even have therapeutic or restorative qualities.

• The soundscape concept is expected to gain more importance in the coming years, providing a more holistic and human-centric approach to shaping our acoustic environments.

Challenges of Soundscape approach

While the soundscape approach offers numerous advantages and insights, it also presents various challenges:

• Subjectivity: Since soundscapes focus on individual perception and experience of sounds, creating objective standards or guidelines applicable to a wide population can be challenging. What's pleasant for one might be disruptive for another.

• Measurement and Quantification: Measuring sound levels is straightforward, but assessing the quality or sensation of a sound is more complex, often requiring subjective evaluation methods that can be inconsistent.

• Interdisciplinary Challenges: The soundscape approach demands collaboration from experts across diverse fields, from acousticians to urban planners to psychologists. This can result in communication barriers and differing methodologies.

• Cost: Comprehensive analysis and design of soundscapes can be expensive, especially when advanced measurement techniques or extensive public participation processes are needed.

• Variable Acoustics: Acoustic environments can change based on factors like the time of day, weather, etc. This variability complicates the task of creating or analyzing a "standard" soundscape.

• Cultural Differences: Soundscape perceptions can vary culturally. What one culture deems pleasant might be disruptive in another.

• Long-term Changes: Acoustic settings can evolve over time due to urban developments, technological advancements, or societal shifts. Soundscapes are not static and require regular review and adjustment.

• Conflicts with Traditional Noise Control: There might be clashes between the traditional noise reduction approach and the soundscape method, particularly concerning resource allocation.

Despite these challenges, the soundscape approach offers vital insights into how people perceive and experience acoustic environments, presenting opportunities to create spaces that are both functional and pleasant.

Conclusion

The importance of understanding and crafting our sonic environments becomes increasingly important. From the health implications of relentless urban noise to the relaxing sounds of nature, soundscapes influence our daily lives in profound ways.

As we design the cities of tomorrow, it's essential to consider not just what they will look like but also what they will sound like. The soundscape approach offers a comprehensive, experience-driven methodology to create both functional and pleasant spaces for living.