Effects of Sound Source Landscape in Urban Forest Park on Alleviating Mental Stress of Visitors: Evidence from Huolu Mountain Forest Park, Guangzhou

Abstract

Urban Forest parks are indispensable areas in cities and have ecological and social advantages, and the quality of their acoustic landscapes is an important factor influencing visitors’ visiting experience. The purpose of this study was to investigate the factors influencing the acoustic landscape on psychological stress relief in selected urban forest parks in China. This study used a questionnaire to construct an index system for psychological stress reduction and designed a questionnaire for the perceived impact of stress-reducing acoustic sources with user perception and stress-reducing restoration evaluation as the entry point. The research team conducted field research and online questionnaire survey on the questionnaire.com platform from 1–5 July 2022, in Huolu Mountain Forest Park, an urban forest park in Guangzhou, and collected 266 valid questionnaires. SPSS26.0 was used to analyze the results of the impact of the urban forest park on users’ psychological stress relief. Spearman’s rho correlation analysis and a Kruskal–Wallis nonparametric test were used to reveal the relationship between social, demographic and behavioral factors of tourism and sound source perception, and multiple regression analysis was used to identify the key factors of urban forest park. The results showed that, first, there were significant individual differences and correlations between respondents’ age, education level, visit time and frequency on soundscape perceptions; the older the respondent or the higher the education level, the higher the psychological stress relief evaluation of natural sounds such as birdsong in urban forest parks; the more frequent the visit, the more sensitive the users were to sound source perceptions; and the different visit time periods showed that, when the frequency of the visit was higher, the more sensitive the users were to the sound source. Secondly, natural sounds are important factors for psychological stress relief in soundscape, and natural sounds such as birdsong, cicadas, flowing water, and the sound of breeze blowing leaves have positive benefits and significant contributions to psychological stress relief. Third, the overall restorative evaluation of soundscape perception and the separate evaluation of natural, mechanical, and human-made sounds had significant effects, and the overall restorative evaluation showed that the cumulative contribution value of attractiveness was greater than that of compatibility and consistency. Fourth, soundscape plays a role in psychological stress relief, as evidenced by significant differences in pleasure and arousal levels but not in control.

1. Introduction

In recent years, the health outcomes of the modern urban environment as a primary place of residence have come under increasing scrutiny [1]. In the wake of the global pandemic of coronavirus disease, the public has ended up increasingly worried about mental fitness in the face of “overwhelming” information about the epidemic, the increasing pressure people feel on a daily basis, the resulting increasing severity of human mental illness and environmental problems and the rapid development of urban forest parks. As the ‘green lungs’ of cities, urban forest parks play an important role in improving air quality, regulating microclimate and protecting biodiversity, among other urban ecosystem services. The soundscape is a section of the study of auditory ecology and is an essential factor affecting the act of visiting a park, and helping to relieve stress and is one of the key factors in achieving psychological and physical rehabilitation and creating a healthy habitat [2]. Soundscape research is now becoming an international hotspot in the field of soundscapes. The Canadian composer and environmentalist Schafer was the first to introduce the concept of ‘soundscape’; he used the time period ”The Music of the Environment” to describe soundscapes, defining them as “the auditory elements of the landscape” [3]. He described soundscape as ‘the aural properties of the landscape’ and posted two books, European Sound Diary and Five Village Soundscape, to promote the concept of soundscape, which also marked the establishment of the field of soundscape studies [4]. Soundscapes classify sounds into three categories: anthrophony, biophony and geophony.

The study has focused on natural soundscapes in forests, and most studies have focused on natural soundscapes in forests [5,6,7]. Understanding the differences in soundscape perception characteristics [8] and their influencing factors is an important way to enhance the soundscape experience and its influencing factors [9]. Therefore, from exploring the variability of sound source perception characteristics and its influencing factors and identifying the impact on soundscape perception by individual feature differences, it can help to effectively improve the soundscape quality in forest parks. The Stress Reduction Theory (SRT) proposed by Ulrich, a scholar in the area of rehabilitation architecture and his theories are the focal point of this study [10]. The acoustic environment consists of multiple sound sources, and understanding the effects of several typical sound sources on stress relief was the focus of this study. The restorative evaluation of stress relief is influenced by psychological and physiological factors [11]. The soundscape study in this paper focuses on the soundscape in an urban forest park, including objective sound environment indicators, soundscape perception evaluation indicators and emotional indicator features, to explore the potential positive soundscape in urban Morley Park and to discover the relationship between a high-quality soundscape and stress recuperation in city Morley Park, so that the positive soundscape features can be utilized. In this way, the superb soundscape traits can be used in the Morley Park for fitness benefits. Taking Huofushan Forest Park in 7 s Guangzhou, China, as the research site, this study selected representative sites of a typical urban park environment where natural, man-made and artificial equipment sounds were extracted. The soundscape appreciation assessment questionnaire used was collected to consider the soundscape of the pattern sites. The objective is to explore the influence of sound source perception on pressure relief in an urban park environment, so as to provide a reference for its design. As shown in theconceptual framework in Figure 1, the specific questions of this study are:

(1)

Will the soundscape of the forest park have an impact on relieving mental stress?

(2)

Which soundscapes are the important factors to relieve mental stress soundscape?

(3)

How can we use soundscape design strategy in forest park restoration?

2. Literature Review

2.1. Urban Forest Park Acoustic Environment Study

Acoustic surroundings perform an essential task in the usual surroundings of city public spaces. People’s sound alleviation is now not solely influenced by means of the sound strain stage of noise but is additionally associated with the kind of sound source, the character traits of the customers (demographic/social factors) and a quantity of different factors. A soundscape is a site-specific acoustic environment, perceived and understood by an individual, team or community [12]. Addressing anthropogenic underwater noise through the Convention on Biological Diversity has led to intensive research in the field of noise control and soundscapes by senior academics from around the world [13]. Aletta examined the conceptual framework of the soundscape model [14]. Wang studied the perception of soundscapes in national parks and their impact on visual aesthetics [15]. Sun, Minkai and Marafa [16,17] did pioneering work in the field of soundscape research in classical Chinese gardens, exploring the creation of soundscapes within classical Chinese gardens from the perspective of sound sources. Li [18] built a sound landscape assessment model for urban public open spaces. Using the Ergo LAB data platform, Cao [19,20] uses physiological metrics to assess the effects of natural and human sounds on stress relief. In the field of urban soundscape research, the study focuses on factors such as the perception, evaluation and influencing factors of soundscapes in different spatial environments such as parks, green spaces and neighborhood’s [21,22,23].

The study of sound environments relies on listeners’ perception and evaluation of the overall sound environment. In their exploration of elements associated with soundscape perception, researchers have discovered that soundscape appreciation is influenced by means of elements such as person, place and environmental experience [24,25]. It also varies greatly between individuals [26]. Differences in the perception of auditory information between individuals are reflected in the different perceptual characteristics of soundscapes [27]. Demographic characteristics differences may determine the way people perceive the sound environment [28,29]. Tervo used spatial decomposition methods for encoding and playback in an anechoic chamber using a loudspeaker playback system. The test results show that this preference depends on the sound engineer and occupation, with the mixing engineer preferring a dry acoustic environment with high clarity. [30] studied acoustic comfort from the perspective of restorative access to the environment to determine “what sounds reduce users’ perceptions of stress”; the results of the study showed that stress perceptions were significantly reduced when users were in an acoustic environment that felt comfortable, while stress perceptions were not significantly reduced when users were at rest and when their preferred sound source was added to the environment. There was no significant reduction in stress perception when users were at rest and when their preferred sound source was added to the environment. The Swedish scholar Hedblom M. et al. compared the effects of panoramic images of cities, forests and parks for visual stimulation, olfactory stimuli and auditory stimuli on physiological stress in urban green spaces and showed that both olfactory and auditory stimuli were significantly correlated with stress reduction, but visual stimuli were not significantly. Both associative and auditory stimuli were significantly correlated with stress reduction, but visual stimuli were not [31]. Walker investigated the effect of mood changes on body width in women with bulimia, selecting before and after controls for the experiment. Body width estimation was performed before and after mood induction using video distortion techniques. Findings suggest that altered emotional states in bulimic women are associated with body perception and habitual emotional quality [32].

2.2. Theoretical Studies Related to Stress Relief

Since the concept of a restorative environment was introduced, two major theories have been developed: First is the ART proposed by using Kaplan and his spouse in 1989, which focuses on the function of the herbal surroundings in relieving cognitive fatigue from the standpoint of “attention restoration”. One is the ART proposed via Kaplan and his spouse in 1989, which explains the position and mechanism of the herbal surroundings in relieving cognitive fatigue and different components of cognitive fatigue [33]. The four primary traits of restorative surroundings are fascination and compatibility, being away and extent. The second is the stress reduction theory, also known as the psychological evolution theory, which emphasises the therapeutic and rehabilitative effects of herbal environments on people’s intellectual stress and illness [34]. Stress reduction theory (SRT) suggests that the process of ‘recovery’ should be explained by ‘psychological evolution’ [35]. The theory suggests that, when individuals in stressful situations are exposed to restorative environments (e.g., forests, parks, etc.), they are attracted to the soundscape and quickly respond psychologically and physiologically accordingly, replacing negative responses with positive ones. The Restorative Benefits of Nature: Towards an Integrative Framework [36] argues that these two perspectives are complementary and can be effective in explaining certain important phenomena: (1) how attentional fatigue and individual stress, respectively, affect information processing, (2) why a person who enjoys, is good at, and is confident at something can still feel physically and mentally, (3) why the two feelings of fatigue and stress are completely different, and (4) why the same task feels stressful at some times and stress-free at others. In summary, there is now general agreement in the field of restorative research that ‘attention recovery’ and ‘stress relief’ are two distinct but mutually influential benefits of restorative environments; both play a key role in people’s working life. Researchers in the field of soundscape research have developed theories of the restorative benefits of soundscapes based on theories of stress recovery, attention recovery and extensive time and exploration of restorative environments [37,38,39,40]. These theories have focused on the facilitative or hindering effects of soundscapes on individuals’ ability to recover from mental fatigue and stressful emotions [41,42]. In addition, knowledge mapping of sustainable building design development was performed using Cite Space software by Guo Yanlong et al. [43]. Seeland et al. [44] suggest that activities inside the park have a positive impact on improving the mood of those who play in the park. Kang et al. [45] also proposed a theoretical framework for the restorative nature of soundscapes, stating that soundscapes have a direct effect on individual recovery in terms of psychological, physiological and attentional aspects, as well as an indirect effect due to audiovisual interactions, and also proposed a semantic description of the restorative characteristics of soundscapes and their counterparts [46].

3. Materials and Methods

3.1. Study Areas

3.1.1. Site Survey of the Study Area

In order to have a more comprehensive picture of the changing pattern of the soundscape of the Huofuoshan Forest Park, the research time was determined to be 18:00–21:00 in the evening, and in July 2022, five consecutive working days were spent on the case study. The study area is in Tianhe District, Guangzhou City and Guangdong Province.

The study area is in the northeastern part of Tianhe District, Guangzhou City, Guangdong Province, south of Guangzhou Highway, bordered by the South China Botanical Garden in the west, Guangdong Tree Park in the north and Da Guan Road in the east. The area is about 3 km in length from north to south, covering 4.1 square kilometer, and the total area of Huofuoshan Park is about 9000 mu. Topography: The average altitude is 150 m, with the highest peak in the central part of the park at 321.8 m above sea level. The mountain is rounded and gently sloping, with boulders of various shapes all over the mountain, and the soil is mostly red clay. The study area has a subtropical monsoon climate: in spring (March to mid-May), there is a temperature and humidity rise and an average temperature of 23 °C and humidity of 82%. In summer (late May to mid-September), temperatures reach up to 33 °C and humidity rises to 90%; in autumn (late September to early December), the average temperature is 23 °C and the average humidity 72%. In winter (mid-December to late February), the average temperature is 17 °C and humidity 72%. In addition, the mountain experiences four seasons, rich in plant configurations and water resources, and is a comprehensive urban forest park integrating ecological protection, recreational green space and educational research. Therefore, Guangzhou Huofuoshan Forest Park was chosen as the study area. The study exploration included the geographical location, general layout, components of the sound environment and its spatial distribution, as shown in Figure 2. Guangzhou Huofu Mountain Forest Park includes three functional areas, namely, plant landscape area, waterfront landscape area and human landscape area, as shown in

Table 1. Basic characteristics of the park environment at the sampling site.

	Sampling Point Classification	Figure Code	Sampling Point	Environmental Characteristics
Park sound source environment E	Waterfront landscape area Ea	Ea1	According to the moon lake view scenic spot	Rich water, big lawn, camping
		Ea2	Longdong Reservoir fishing area	The water is clear and clean
		Ea3	Colorful jade tan edge playing water area	Stream leisure, water edge entertainment
	Plant landscape area Eb	Eb4	Zhuyuan View Scenic Spot	Bamboo forest plants are dense.
		Eb5	Lotus pond side	The lotus is open.
		Eb6	Under the youth forest streetlamp	The dense trees and the level of the plant landscape
	Cultural landscape area Ec	Ec7	White frame top stone steps road	The main peak of the furnace mountain, round mountain, gentle slope, natural stone slide
		Ec8	Zhutou stone viewing platform	Supported by two small boulders, round rolling stone, big stones everywhere, overlooking the city view, stone steps road
		Ec9	Jizhen Stone breeze pavilion	The rocks are composed of black mica granite, ladder path, ancient style charm

.

3.1.2. Types of Sound Sources in the Study Area

The source type is the primary acoustic factor influencing soundscape perception. The source type is the primary acoustic factor influencing the perception of a soundscape The definition of source type is important for the evaluation of soundscape perception, and the classification of a sound source is important for the quality of the soundscape perception [47]. The park contains a rich soundscape, and with reference to previous studies [48], nine data sampling points were selected in three functional areas based on the principles of accessibility and representativeness before formal data collection. As shown in

Table 2. Urban forest park sound landscape elements.

	Sound Source Type 2	Sound Source Name 3
Q: Furnve Mountain Forest Park	Qa: Natural sound	Qa1: The sound of the leaves
		Qa2: The sound of water flow
		Qa3: bird song
	Qb: Artificial equipment sound	Qb1: traffic sound
		Qb2: Broadcast music sound
		Qb3: construction site construction sound
	Qc: Human activity voice	Qc1: talk
		Qc2: footsteps
		Qc3: sweeping the floor

, natural, artificial equipment sound and human activity sound sources were considered. Specifically, four typically natural sound sources were chosen for analysis: insects chirping, breeze blowing leaves, water flowing and birdsong; four typically artificial equipment sound sources were chosen for analysis: traffic sounds, radio and music sounds, aircraft flying over and construction site sounds; and four typically human activity sound sources were chosen for analysis: children playing, footsteps, adults communicating and cleaners sweeping the floor.

3.2. The Questionnaire Design

3.2.1. Basic User Information

Research has shown that individual characteristics of a user (demographic/social factors) have an impact on the evaluation of soundscape stress reduction, with Miedema and Vos [49] showing that demographic/social factors such as age, gender, occupation and educational background are influential factors in the user’s perception of noise. The questionnaire for this study was divided into two parts, so the former part was designed to provide information on the social, demographic and behavioral aspects of the users. The questionnaire contains information on gender, age group, educational background, type of residence and behavioral characteristics, including age (18 and below, 18–30, 31–40, 41–50, 50 and above), educational (junior high school and below, high school and college, undergraduate and postgraduate); behavioral indicators include the frequency of park use in a week (1 time and below, 2–3 times, 3–5 times, 6 times and above) and time period of park visit (early morning 5:00–8:00, 8:00–11:00 a.m., 11:00–13:00 p.m., 13:00–18:00 p.m., 18:00–21:00 p.m., 21:00–24:00 p.m.), as shown in Figure 3.

3.2.2. Evaluation Scale

The second part of the study was conducted through on-site field research, based on which the site was divided into three areas: waterfront landscape area, plant landscape area and human landscape area. The soundscape was collected through the site and made into audio. The questionnaire was divided into two main areas: soundscape in restorative perception evaluation and soundscape in emotional stress relief. Attentional restorative theory suggests that an individual’s ability to orientate attention depends on the inhibitory capacity of the central nervous system. The Perceived Restorative Ness Soundscape Scale (PRSS), developed by Payne 18, is one of the components of this questionnaire, which is a study based on attention recovery theory, using the Perceptual Resilience Scale (PRS) as a reference, a three-dimensional framework of fascination, compatibility and extent. The “stress relief” theoretical perspective proposes that, in psychological terms, personal stress is influenced by the restorative environment and that the external response to psychological factors is mainly in the form of changes in individual mood. Respondents’ emotional state was assessed on the basis of their subjective self-assessment, and this section of the study used the characteristic dimensions of the Self-Assessment Manikin (SAM) scale, which measures three dimensions of emotional response: pleasure, arousal and control. These three trait dimensions are seen as the core traits of emotional influence in psychological research [50,51].

In this study, there are three aspects of the overall assessment of the urban forest park soundscape by park users, the degree of soundscape perception and the three emotional dimensions of users and the comprehensive audiovisual evaluation, which were used as evaluation indicators to alleviate mental stress [52,53,54]. Each evaluation index was measured using a 9-point Likert scale method, with each dimension corresponding to a score of 1 to 9. The above scale was designed based on Kaplan’s theory of attention recovery, the ideas of Ulrich’s stress relief theory and the Self-Revaluation Recovery Scale (SRRS), which was developed by Han, a Taiwanese scholar in China, who simultaneously integrated the two theories of attention restoration and stress relief and SRRS [55].

3.2.3. Assessment System Construction

This study is based on theories of attention restorative and stress relief. Scholars in various fields have conducted a large number of studies on stress relief and the main research methods have been broadly classified into two types: subjective evaluation options and objective validation options. Therefore, the idea of this study is to conduct a wide range of subjective evaluations of stress-relieving soundscape elements for a large number of respondents to explore their subjective perceptions of stress-relieving soundscapes, as well as to explore potentially stress-relieving soundscape elements, and to investigate the impact of urban forest parks on stress relief for the general public. This study uses hierarchical analysis based on the content of the scale to construct an evaluation system of the impact of soundscape perception on stress relief. By dividing the system into multiple levels from top to bottom, the indicators of each level of the evaluation system are clearly constructed, including three levels: target level V, criterion level and evaluation factor level.

The first target layer is divided into “Urban forest park sound source perception restorative evaluation V1” and “emotional stress relief V2”, while the criterion layer is a layer below the target layer, which refers to a series of factors that have an impact on this target layer, and the criterion layers in this paper correspond to the third layer, which is the evaluation factor layer, a reflection of the second criterion layer, and the indicator layer refers to the factors that have an impact on the factors in the criterion layer. The hierarchy of the evaluation system derived from this study is shown in

Table 3. Hierarchy of soundscape perception evaluation systems.

Level 1 Indicator (Target Layer)	Secondary Index (Standard Layer)	Specific Description (Evaluation Factor Layer)
V1: Evaluation of sound source perception recovery	V1a: compatibility	Unaccustomed, uncomfortable, incompatible-customary, adaptive, compatible
	V1b: Extent	Diligent, messy, uncoordinated-consistent, harmonious and coordinated
	V1c: Fascination	Annoying, repellent-fascinated, engaging
V2: Emotional stress relief	V2a: Pleasure	Nasty, bad, sad, upset (negative mood) -Like, good, happy, happy (positive mood)
	V2b: Arousal	Calm, relaxed, sleepy-tense, exciting, exciting
	V2c: Dominance	Feel weak to control the voice-feel strong and able to control the voice

.

3.3. Methods

3.3.1. Survey Methodology

The Urban Forest Park users’ evaluation survey was conducted to understand the evaluation and a method for evaluating the effectiveness of park soundscape perception on stress relief for users. Members of the research team conducted field research in Huofu Mountain Forest Park in Guangzhou from 1 July to 5 July 2022 by communicating with visitors, allowing park users to conduct an online questionnaire and tallying the basic information of all respondents, The online questionnaire was distributed on the questionnaire website on 5 July 2022 and collected on 20 July, with an interval of 15 days between distribution and collection. A total of 300 questionnaires were distributed, and 281 questionnaires were collected, with a return rate of 93.67%. After excluding the questionnaires with incomplete or obviously wrong answers, 266 valid questionnaires were collected, with a validity rate of 88.67%. Data entry was carried out in an impartial and objective manner by professionally trained researchers from the research team to ensure that the data entry process was carried out correctly.

Customers had been requested to fill in the questionnaire while experiencing audio and video of the soundscape in the park, and the data was analyzed in a simple statistical way before being entered into the statistical analysis software SPSS 26.0. This study uses hierarchical analysis based on the content of the scale to construct an evaluation system of the impact of soundscape perception on stress relief, and Spearman’s rho correlation analysis and a Kruskal Wallis non-parametric test to reveal the relationship between the social, demographic and behavioral factors of visitors and the degree of sound source perception and finally uses multiple regression analysis to identify the key sound source perception factors of urban forest parks on stress relief. The key sound source perception factors of the urban forest park were identified using multiple regression analysis.

3.3.2. Confidence Analysis

Reliability refers to the consistency and stability of size results, and Cronbach’s alpha is a reliability analysis using SPSS software to measure the internal consistency, or reliability, of an instrument or questionnaire. It is most commonly used in questionnaires developed using multiple Likert scales to determine whether the scale is reliable. The Cronbach’s alpha reliability coefficient is calculated because the results of the Cronbach’s alpha reliability calculation more accurately reflect the actual reliability [56].

The reliability of the questionnaire is the guarantee of the study, and this study was conducted Cronbach’s reliability analysis in SPSS 26.0. As shown in

Table 4. Reliability analysis.

Cronbach’s α	Cronbach’s α Based on Standardized Items	Number of Terms	Number of Samples
0.967	0.969	33	266

, the standardized Cronbach’s coefficient is 0.969. The range of values of the reliability coefficient is between 0 and 1 and being closer to 1 indicates better reliability. The model has a Cronbach’s alpha coefficient value of 0.969, and the reliability of the questionnaire is excellent, thus ensuring that the credibility of the survey meets the basic requirements of this questionnaire and that a series of subsequent analytical studies can be conducted.

3.3.3. Validity Analysis

Before conducting the exploratory factor analysis [57], the data needed to be analyzed for validity. The validity of this questionnaire was analysed in SPSS 26.0, an exploratory factor analysis method to test for structural validity. As seen in the results, the validity of the data was analysed using Bartlett’s spherical test and KMO, as shown in

Table 5. The KMO test and the Bartlett’s test.

KMO Price		0.968
Bartlett sphericity test	Approximate chi square	14,675.780
	df	703.000
	p	0.000 ***

Note: *** represents a significance level of 1%.

. The results show that the KMO value of 0.968 indicates that the data collected can be analyzed by factor analysis. The coefficients of the KMO vary from zero to 1, and the nearer the coefficient is to 1, the more questionnaire is valid. Meanwhile, the effects of Bartlett’s spherical check confirmed that the magnitude p-value was once 0.000 ***, which confirmed value at that level, that the authentic speculation was once rejected, that there was once correlation between the variables, and that the issue evaluation was once legitimate to the extent that it used to be suitable.

4. Results

4.1. Analysis of the Role of Soundscape Perception Recovery

4.1.1. Sound Source Restorative Perception Characterization

Research on restorative theory suggests that the premise of “restoration” is that the individual is in a “depleted” state, emphasizing the process of returning from a negative state to a natural state [58]. Taking nine typical sound sources in the Huohuoshan Forest Park area of Guangzhou as an example, the compatibility, coordination and attractiveness of each sound source were classified according to the median (IQR) and mean (SD) of the restorative perceptual evaluation of the compatibility, coherence and attractiveness of the various types of sound sources, as shown in

Table 6. The mean value and standard deviation of the emotional evaluation of each sound source.

Sound Source Type Q/Soundscape Perception V	Natural Sound Qa			Artificial Equipment Sound Qb			Human Activity Sound Qc
	Qa 1	Qa 2	Qa 3	Qb 1	Qb 2	Qb 3	Qc 1	Qc 2	Qc 3
Compatibility V1a	6.96 * (2.11)	6.37 * (2.73)	6.67 * (2.25)	3.14 * (2.54)	3.33 * (2.32)	2.85 * (2.46)	5.14 * (2.09)	4.82 * (2.03)	5.26 * (2.07)
Extent V1b	6.38 * (2.73)	6.41 * (2.73)	6.66 * (2.33)	3.01 * (2.40)	3.27 * (2.45)	2.75 * (2.33)	5.27 * (2.15)	4.84 * (1.98)	5.32 * (2.13)
Fascination V1c	6.38 * (2.80)	6.71 * (2.28)	6.70 * (2.36)	3.05 * (2.54)	3.33 * (2.41)	2.76 * (2.44)	5.23 * (2.17)	4.90 * (1.98)	5.28 * (2.18)
F	1.096	0.804	1.571	6.954	7.211	10.775	9.677	3.647	2.433
P	0.296	0.371	0.211	0.009 ***	0.008 ***	0.001 ***	0.002 ***	0.057 *	0.12

Note: M (SD) = mean value (standard deviation); Median (IQR) = median (interquartile spacing); ***, and * referring to 1%, and 10% of respectively.

. The median compatibility of each sound source for stress relief is specifically highest for the sound of water flow (6.96), followed by the sound of birdsong (6.67) and the sound of breeze blowing leaves (6.37), which shows that the natural environment has the greatest influence on restorative compatibility for stress relief. The sound of construction sites (2.75), vehicles moving through (3.01) and radio music (3.27) have a lower impact on the compatibility of stress relief, and these sound categories are all artificial equipment sounds. In terms of sound source perception compatibility with the surrounding environment, birdsong (6.66) has the highest compatibility with the surrounding environment, followed by water flow (6.38) and breeze blowing leaves (6.41), all of which are natural sounds, while the lowest compatibility with the surrounding environment is for construction sounds (2.75), followed by vehicle traffic sounds (3.01) and radio sounds (3.27), all of which are artificial equipment sounds. This is related to the current positioning and function of Huofuoshan Forest Park in Guangzhou. The rapid urbanization process has accelerated the development of industry, and the large amount of urban construction in the city has led to high levels of artificial equipment sound. In terms of the degree of attraction of sound sources to users, natural sounds have a higher attraction, with respondents having a higher attraction to the sound of breeze blowing leaves (6.71) and birdsong (6.7), both above 6.70, both of which are natural sounds, and the lowest attraction to construction site sounds (2.76).

When discussing the standard deviation of factors for evaluating sound perception, respondents had a very high standard deviation of 2.73 for the evaluation of the natural sound of a breeze blowing leaves, and the highest SD of 2.73 was for natural sounds of water flowing and breeze blowing leaves in coordination. The highest SD of 2.54 was for vehicles moving through. Natural sounds had a higher SD of their restorative perceptual evaluation compared to other sound sources. This may be due to the differences in the needs of different respondents regarding the acoustic environment in urban forest parks, as some respondents in the interviews stated that they “need a relatively quiet park environment during their visit to the park” but that “visitors should communicate appropriately in the park, but they should keep their voices down during the process”. There is a need to be in close contact with nature.

In general, the overall high and low subjective ratings of soundscape perception by users of the Huofuoshan Forest Park area in Guangzhou show that respondents rated the compatibility, coordination and attractiveness of natural sounds in the urban forest park as autonomously restorative on average, while respondents rated the compatibility, coordination and attractiveness of the artificial sounds present in the park as mostly acceptable, the compatibility, coordination and attractiveness of artificial equipment sounds were still mainly rated as uncomfortable, uncoordinated and unattractive. As shown in Figure 4, the overall subjective evaluation of natural, man-made and artificial equipment sound sources in the urban forest park can be seen by comparing them: natural sound > human activity sound > artificial equipment sound. From this we can see that the sounds that identify urban forest parks in Guangzhou are those that are more compatible, harmonious and attractive, such as birdsong, running water and breeze blowing leaves, followed by man-made sounds. This also reflects the fact that individuals’ perception of the soundscape in urban forest parks is related to the fact that urban forest parks are less influenced by traffic, that people’s activities are mainly ornamental and resting and that the soundscape is mostly composed of birdsong, running water and the sound of the breeze blowing the leaves. This is also evidence of the characteristics of the soundscape: it is an inseparable component of the landscape as a whole, and the two are closely related.

4.1.2. Analysis of the Effect of Soundscape Perception on Psychological Stress

The effect of the soundscape on respondents’ emotional stress was investigated in terms of the emotional indicators mentioned in the “stress relief” theory (including pleasantness, arousal and control). Higher ratings of pleasure and control indicate better emotional resilience, while higher ratings of arousal indicate poorer emotional resilience. A rating of less than five indicates a negative emotional response and more than five indicates a positive emotional response; a rating of less than five indicates that the soundscape calms the respondent and more than five indicates that the soundscape excites the respondent; a rating of less than five indicates a poor emotional control and more than five indicates a good emotional control.

The consequences of the impartial samples that Kruskal-Wallis took a look at confirmed that there have been sizable variations between soundscapes in the restoration impact of the respondents’ pleasure (p < 0.001) and arousal (p < 0.001) but not in terms of control (p > 0.05). The analysis of the park’s subjective evaluation of its emotional perceptions is shown in

Table 7. Effect of soundscape perception on psychological stress.

	Pleasure *		Arousal		Dominance
	Average	SD	Average	SD	Average	SD
Natural sound	6.823 *	2.244	3.173 *	2.234	4.053 *	1.899
mechanic sound	2.756 *	2.441	6.959 *	2.109	4.838 *	1.981
Man-made sound	4.898 *	1.976	5.316 *	2.128	4.898 *	1.976
F	1.870		4.595		9.900
P	0.000 ***		0.002 **		0.066 *

Note: ***, ** and * refer to 1%, 5% and 10% of respectively.

, where the emotional control scores for each soundscape were less than five, indicating that the urban forest park soundscape had a negative effect on respondents’ emotional control. In terms of emotional pleasantness, the natural sounds of the park promoted a greater sense of emotional pleasure and calmness than the man-made sounds or the mechanical sound control environment. In terms of emotional arousal, the park mechanical sound arousal was greater than five, indicating that the mechanical soundscape tended to make respondents emotionally tense and excited, while the natural soundscape made respondents feel calm. Overall, the psychological stress restorative effect of the soundscape experience of natural scenes in the park was higher.

4.1.3. Sound Source Perception Restorative Effects

To obtain the impact on the perceived restorability of the scene in the Fireplace Mountain Forest Park in Guangzhou, factor analysis was conducted separately for the perceived restorability of the soundscape for each of the different sound source types. Factor analysis allows clustering into several main factors based on the degree of correlation between the original variables, which is helpful in explaining and elucidating the intrinsic associations between these main factors. The good reliability and validity of the data, as seen above, indicates that the type of variables and the sample size of the scale results meet the necessary conditions for factor analysis. In the soundscape restoration evaluation scale, three types of sound sources were used as the entry points, and the nine sub-questions were used as the project units. The factor loadings of each variable were obtained by using the Varimax-rotated method as the factor rotation method. The horizontal coordinates of the graph show the number of common factors, and the vertical axis indicates the magnitude of the eigenvalues. The first two common factors in the scree plot have the largest eigenvalues (greater than eight), and the scatters of the first two common factors are located on steep slopes, both of which have eigenvalues greater than one, and are therefore the main common factors to be considered. The remaining scatters of the latter factors form gentle slopes and platforms, and all have eigenvalues less than one, indicating a weaker role.

The results of the analysis show that the same two public factors were extracted at the end of both the overall evaluation and the separate evaluations of natural, mechanical and anthropogenic sounds and that these public factors had a significant effect on the information description of the original variables, as shown in

Table 8. Factor analysis.

Project	All the Sound			Natural Sound			Artificial Equipment Sound			Human Activity Sound
	Considerations 1 18.39%	Considerations 2 20.53%	Considerations 3 22.01%	Considerations 1 30.33%	Considerations 2 31.60%	Considerations 3 32.65%	Considerations 1 30.93%	Considerations 2 30.93%	Considerations 3 31.20%	Considerations 1 30.44%	Considerations 2 30.36%	Considerations 3 30.53%
1	0.864	0.865	0.878	0.937			0.930			0.919
2	0.871	0.885	0.844	0.948			0.933			0.906
3	0.843	0.876	0.864	0.937			0.925			0.921
4	0.224	0.262	0.272		0.954			0.947			0.910
5	0.334	0.381	0.334		0.954			0.936			0.908
6	0.229	0.247	0.237		0.936			0.926			0.909
7	0.888	0.884	0.879			0.928			0.947			0.912
8	0.880	0.879	0.877			0.954			0.942			0.911
9	0.899	0.888	0.908			0.954			0.903			0.935

. This indicates that respondents perceived the restorative nature of the soundscape in three main ways, which were named: compatibility (including nine items), coherence (including nine items) and attractiveness (comprising nine items). For different types of sound, the weighting of each factor varies: an integrated assessment of the sounds that exist in nature and the city, the cumulative contribution of these three factors reached 54.90%, with compatibility accounting for 18.39%, coordination for 20.53% and attractiveness for 22.01%; for the evaluation of natural sounds, the cumulative contribution of these three influences amounts to 89.28%, with compatibility accounting for artificial equipment sound, and the cumulative contribution of these three influences amounts to 86.91%, with compatibility accounting for 30.93%, coordination for 30.93% and attractiveness for 31.20%; for human sound, the cumulative contribution of these three influences amounts to 83.65%, with compatibility accounting for 30.44% and coordination for 30.44%. The cumulative contribution of the three elements to the assessment of human sound was 83.65%, with 30.44% for compatibility, 30.36% for coordination and 30.53% for attractiveness. It can be found that the cumulative contribution of attractiveness to the evaluation of the perceived restorative soundscape is greater than that of compatibility and coordination, and therefore the attractiveness factor (attractiveness) is a more important attribute of the restorative soundscape in the study.

4.2. Relationship between Demographic and Social Factors and the Restorative Evaluation of Sound Source Perceived Pressure

Respondents’ perceptions of the acoustic environment in urban forest parks vary according to demographic/social factors [59]. A strong correlation was found between social, demographic and behavioral elements and the understanding of sound sources. In this study, two methods, Spearman’s rho correlation and a Kruskal–Wallis non-parametric test, were used to reveal the relationship between visitors’ social, demographic and behavioral factors and the degree of sound source perception.

Table 9. Analysis of recovery and social and demographic factors.

Health Benefit Research		Gender	Age	Educational Background	Weekly Tour Frequency	Access Time Period
Sound source perception recovery	Compatibility	0.394	0.000 ***	0.000 *** (0.000 ***)	0.004 *** (0.001 ***)	0.002 *** (0.005 ***)
	Extent	0.087 *	0.026 **	0.992	0.259	0.554
	Fascination	0.019 ** (0.018 **)	0.386	0.834	0.523	0.219 (0.016 **)
Emotional stress recovery	Pleasure	0.102	0.191	0.776	0.442	0.260 (0.018 **)
	Arousal	0.001 *** (0.001 ***)	0.063 *	0.001 *** (0.000 ***)	0.004 *** (0.000 ***)	0.000 *** (0.000 ***)
	Dominance	0.270	0.000 ***	0.000 *** (0.001 ***)	0.011 ** (0.006 ***)	0.005 *** (0.016 **)

Note: Spearman’s rho correlation coefficient. * expresses p < 0.1, ** expresses p < 0.05, and *** expresses p < 0.01.

shows the correlation and variance analysis data. In terms of sound source perception recovery, the influence of age and educational background on the perception of soundscape is more obvious, specifically: age is the most significant user characteristic, the older the person is, the higher the rating of compatibility with natural sounds such as birdsong in urban forest parks, and the lower the rating of compatibility with human language sounds, and older people have a higher degree of coordination and attraction in urban forest parks than younger people; this is followed by educational backgrounds, with more educated people perceiving sound sources as less restorative and less compatible with the soundscape. The higher the frequency of visits, the more sensitive users are to the perception of sound sources. The degree of attractiveness of the soundscape was rated differently depending on the time period of the visit. In terms of emotional stress resilience, emotional arousal was significantly related to the time of the visit, with respondents using the park as a public place for recreation and exercise in the early morning (6:00–8:00 a.m.) and in the evening (18:00–20:00 p.m.). Emotional arousal was significantly correlated with gender, educational background, frequency of visits and the time period of visitation. The higher the educational background, the more sensitive the perception of emotions and the higher the overall perception of emotional stress restorative requirements; the more frequent the visits, the more nervous and excited people feel about man-made and artificial equipment sounds and the calmer they feel about the natural environment around the park, and as the frequency of visits increases, the negative effect of artificial equipment sounds on emotions becomes more pronounced. The time period of the visit was significantly correlated with the degree of emotional pleasure, arousal and control.

4.3. Key Factors in Stress Relief Effectiveness

To identify key elements of sound source perception for pressure mitigation in urban forest parks, this study used soundscape perception (pleasantness, arousal, control) and emotional stress (pleasantness, arousal, control) as dependent variables and facts from nine sound sources and respondent statistics as impartial variables, respectively. Due to the massive quantity of impartial variables, we used more than one stepwise linear regression in order to discover the elements that satisfactorily defined the structured variables.

The consequences are proven in

Table 10. Results of a multiple stepwise regression analysis of the effect of sound source perception on stress resilience.

Results of the Linear Regression Analysis n = 266
Dependent Variable	Argument	Non-Standardized Coefficients		Standardization Coefficient	t	p	VIF	F
		B	Standard Error	Beta
compatibility V1a (R2 = 0.809)	constant	0.752	0.227	0	3.317	0.001 ***	-	F = 275.977, p = 0.000 ***
	Qa3 twitter	0.297	0.061	0.298	4.864	0.000 ***	5.134
	Qc1 People’s voice	0.244	0.046	0.227	5.33	0.000 ***	2.469
	Qa2 The sound of water	0.244	0.046	0.227	5.33	0.000 ***	2.469
	Qa3 The breeze blows through the leaves	0.188	0.053	0.229	3.583	0.000 ***	5.571
extent V2b (R2 = 0.797)	constant	0.529	0.271	0	1.952	0.052 *	-	F = 255.534, p = 0.000 ***
	Qa3 twitter	0.411	0.062	0.422	6.594	0.000 ***	5.249
	Qc3 The floor sound	0.254	0.046	0.238	5.471	0.000 ***	2.425
	Qa2 The sound of water	0.246	0.053	0.296	4.684	0.000 ***	5.125
	Q4 Browse frequency	0.204	0.066	0.087	3.088	0.002 ***	1.019
Fascinate V3c (R2 = 0.807)	constant	0.957	0.323	0	2.968	0.003 ***	-	F = 180.002, p = 0.000 ***
	Qa3 twitter	0.337	0.06	0.351	5.619	0.000 ***	5.236
	Qc1 People’s voice	0.26	0.043	0.249	6.002	0.000 ***	2.306
	Qa2 The sound of water	0.198	0.051	0.245	3.854	0.000 ***	5.422
	Qa3 The breeze blows through the leaves	0.138	0.067	0.059	2.054	0.041 **	1.107
	Q4 browse frequency	−0.077	0.036	−0.06	−2.135	0.034 **	1.074
	Q5 access time period	0.122	0.06	0.123	2.025	0.044 **	4.96
Pleasure V2a (R2 = 0.833)	constant	0.226	0.219	0	1.032	0.303	-	F = 166.225, p = 0.000 ***
	Qa3 twitter	0.145	0.064	0.145	2.249	0.025 **	6.628
	Qc3 The floor sound	0.148	0.047	0.14	3.145	0.002 ***	3.16
	Qa1 The sound of water	0.198	0.051	0.245	3.854	0.000 ***	5.422
	Qc2 People’s voice	0.139	0.05	0.129	2.782	0.006 ***	3.429
	Qa2 The breeze blows through the leaves	−0.077	0.036	−0.06	−2.135	0.034 **	1.074
Arousal V2b (R2 = 0.852)	constant	0.433	0.093	0	4.643	0.000 ***	-	F = 254.511, p = 0.000 ***
	Qb1 The sound of vehicles walking through	0.166	0.059	0.189	2.803	0.005 ***	8.144
	Qb3 Site construction sound	0.171	0.064	0.179	2.664	0.008 ***	8.043
	Qb2 Radio music	0.131	0.058	0.144	2.277	0.024 **	7.123
Dominance V2c (R2 = 0.786)	constant	0.175	0.227	0	0.769	0.443	-	F = 109.171, p = 0.000 ***
	Qb1 The sound of vehicles walking through	0.192	0.053	0.248	3.604	0.000 ***	5.853
	Qb3 Site construction sound	0.122	0.059	0.127	2.076	0.039 **	4.661
	Qb2 Radio music	0.17	0.045	0.22	3.748	0.000 ***	4.265
	Qc2 footstep	0.138	0.05	0.155	2.783	0.006 ***	3.826
	Qc3 The floor sound	0.154	0.053	0.207	2.915	0.004 ***	6.23
	Qa1 The sound of water	0.142	0.045	0.21	3.148	0.002 ***	5.507
	Qa2 The breeze blows through the leaves	−0.134	0.049	−0.161	−2.749	0.006 ***	4.257
	Qc2 People’s voice	0.119	0.05	0.131	2.383	0.018 **	3.722
	Q3 educational background	0.142	0.056	0.075	2.527	0.012 **	1.103

Note: ***, ** and * referring to 1%, 5% and 10%, respectively.

, and, from the evaluation of the consequences of the F-test, it can be concluded that the value p-value is 0.000 ***, and the degree gives significance, rejecting the unique speculation that the regression coefficient is 0. For variable co-linearity performance, the VIF is all less than 10. By testing both the tolerance and VIF, the model established in this study does not have serious co-linearity problems, and the combination of t-test and significance shows that this model is reliable. Therefore, the mannequin has no multicollinearity issues, and the mannequin is properly constructed.

It has been proven that R² represents the match of the curve regression, and the nearer to 1, the higher the effect. As can be seen from Table 10, the curve regression of the impact of soundscape on stress restorability is fantastically excellent, in terms of the overall degree of stress relief for users after excluding their own influence. From the point of view of the recoverability of the perceived sound source, the standardized coefficients for compatibility show that birdsong, children’s playfulness, the sound of water running and the sound of a breeze blowing through leaves all have a fine impact on the compatibility of stress relief. This suggests that the ecological environment and animal diversity in urban forest parks need to be protected in order to further improve users’ sense of stress-relieving comfort; for overall compatibility with the surrounding environment, bird song has the greatest positive effect in terms of the standardized coefficient, followed by water flow and sweeping sounds and browsing frequency, although the positive effect of browsing frequency is lower, but it can be seen from the data that browsing frequency also has a partial effect. Although the positive effect of browsing frequency is low, it can be seen from the data that browsing frequency has a partial effect on the coordination of the urban forest park; in terms of the standardized coefficients in the overall attractiveness degree, bird song, water flow, breeze blowing leaves, children’s playfulness and the time period of the visit have a positive effect on the attractiveness degree of people, while the frequency of people browsing the park has a negative effect on the attractiveness degree. In terms of emotional stress recovery, from the standardized coefficient of pleasantness, birdsong, sweeping sounds, water flowing sounds and human speech all have a positive effect on stress relief compatibility, but the sound of breeze blowing leaves has a negative effect, indicating that the park is more relaxing and calming when the breeze is blowing leaves; from the standardized coefficient of arousal, the sound of vehicles moving through the park, construction site sounds and radio and music sounds have a positive effect. From the standardized coefficients of control, the sound sources of vehicles, construction site sounds, radio and music sounds, footsteps, sweeping sounds, water flowing sounds, human activity voices and educational backgrounds are positively influenced, while the sound of breeze blowing leaves is negatively influenced. This reflects the fact that the greater the stage of education, the more demand there is for emotional stress recovery in the forest park.

5. Discussion

5.1. Forest Park Soundscape Will Have an Impact on Relieving Mental Stress

The results of the emotional stress relief study suggest that soundscapes have a role in heart stress relief, as evidenced by significant differences in levels of pleasure and arousal but no meaningful differences in control and a small, negative effect. This is consistent with previous psychological models of emotion theory, wherein individuals’ emotions are primarily reflected in emotional valence and emotional arousal, while emotional control has shown different results across studies. Therefore, research on the restorative follow-up of soundscapes on respondents’ emotions should pay extra attention to pleasantness and arousal. Increasing the arousal of specific types of man-made, natural and artificial device sounds in urban forest parks may increase users’ perceived control of soundscapes and improve perceptions of their restorative nature, yet such high-quality effects are not evident now. Both the comprehensive restorative evaluation of soundscape perception and the separate evaluation of natural, mechanical and anthropogenic sound have a significant effect, wherein the cumulative contribution values of the three factors in the three source types are ranked as follows: natural sound evaluation > man-made equipment sound evaluation > anthropogenic activity sound evaluation, with cumulative contribution values of 89.28%, 86.91% and 83.65% respectively, and the overall restorative evaluation of each source shows the cumulative contribution value of attractiveness is greater than that of compatibility and coherence.

5.2. Natural Sound Is an Important Factor in Mental Stress Relief in the Sound Landscape

The results of this study suggest that nature sounds can alleviate mental stress to some extent. The results validate Kaplan and Kaplan and Ulrich’s theory that nature sounds promote emotional reflection, evoke positive emotions, generate attention to the environment, influence mental relaxation and promote behavior [60,61]. Multiple linear regression analysis found that natural sounds such as birdsong, cicadas and running water contributed significantly to the positive benefits of mental stress relief. This supports previous findings that birdsong triggers an emotional connection with the natural environment [62] and that birdsong has a positive impact on mental stress relief [63,64]; however, the restorative effects of birdsong are also influenced by the species of birds, so that in urban parks with artificial elements, the stress-relieving effect can be enhanced by adding soothing or popular bird songs. The addition of soothing or well-known bird songs can embellish the stress-relieving effect. Cicadas can be exhilarating; running water can create a sense of ‘comfort’, ‘relaxation’ and ‘nature’ [65], and the sound of strolling water is a necessary aspect of restoring herbaceous spaces. Not only does it reduce a certain amount of noise, but it is also a calming experience. Listening to the sound of walking water in a naturopathic place, for example, is more likely to help humans meditate, sit and relax. The safety of the ecological range and the security of the surroundings in an urban woodland park setting, as well as the fabulous and sensible use of panoramic elements such as streams and waterfalls, can also help to mitigate the harsh results of an urban woodland park. The sound of the breeze blowing through the leaves can also have a positive effect on stress relief [66] but to a lesser extent. Properly ensuring that the sound of a breeze blowing through the leaves in a park may contribute to the stress-relieving effects of urban forest parks, but the effects of stress relief can be influenced by factors such as volume level, the exact location of the sound source and seasonal changes. These results inform research on sound perception for mental stress relief, but in sound perception, the sound source is the dominant factor, and the balance and interaction between several sound sources are also factors to consider. For example, Kogan [67] studied the use of the green soundscape index (GSI) to evaluate the balance between natural sound and traffic noise, and the GSI offers prospects for the application of environmental sound source separation techniques.

5.3. Forest Park Restoration Soundscape Design Strategy

According to the research results, the natural sounds of birdsong, breeze blowing, blowing leaves, insects and running water are positive recovery benefits. Protecting and creating a restorative soundscape in soundscape design is an important means [68,69]. In the protection and creation of natural environmental sound sources such as birdsong, insect chirping and the sound of running water, attention should be paid to the protection of biodiversity and natural stream resources, so as to provide a good habitat space for birds and other animals, and bird-leading plants can be planted. In addition, shallow water can be used to set up stones or stakes to attract birds. For the sound of running water, on the one hand, it can be created through physical means, such as using stones to change the width of the stream, guide the flow or prevent the water to create more interesting sound, create the drop and create water drops, and, on the other hand, creating the opportunity to listen to the meditation platform and to rest. For the wind and wind blowing leaves can be configured with bamboo plants. In order to reflect the landscape characteristics of urban forest parks, soundscape must be integrated into the planning and advent of city woodland parks, and with the aid of exploring the particular effect of soundscape appreciation assessment in the assessment of landscapes in city woodland parks, a more comprehensive planning tool should be provided for the development and renewal of urban forest parks.

6. Conclusions

Soundscape appreciation assessment questionnaire used to be used to investigate the extent to which the soundscape used to be perceived in the city park environment. The purpose was once to look at whether or not the city park surroundings can relieve stress and to inspect whether or not the depth of a soundscape is a vital issue in restoring the soundscape. The important findings are as follows:

(1)

The stress-relieving effect of urban parks is altered by the addition of soundscapes, which are an important part of the overall landscape, and the two are closely related. In the restorative results of this study, in terms of sound source types, the most restorative potential in urban forest parks is not only for natural sounds but also for anthropogenic sounds. The individual perception of soundscapes in urban forest parks is related to the fact that urban forest parks are less affected by traffic and that crowd activities are mostly ornamental and restful, and the positive contribution of birdsong, running water and breeze blowing leaves to the stress-reducing effect is significant and consistent with previous studies.

(2)

The positive impact of the Guangzhou Urban Forest Park on the restorative evaluation of emotionally stressful soundscapes is mainly reflected in the levels of pleasure and arousal, with significant differences between different types of soundscapes in terms of pleasure and arousal levels, and no meaningful differences in terms of control. Attractiveness has a greater cumulative contribution value relative to compatibility and coherence, and attractiveness is a more important trait for restorative soundscapes in this study compared to others.

(3)

In the relationship between the demographic, social and overall perception of the human soundscape, there were significant individual differences and correlations between respondents’ perceptions of specific sound sources and soundscapes, with the effects of age and educational background on the perceived restorability of sound sources being more pronounced. Non-acoustic elements such as gender, age, academic historical past and time length of visits have been additionally influenced. In terms of emotional stress relief, there is a vast distinction in the stress-relieving consequences of park soundscapes for men and women, and therefore research and the design of restorative soundscapes for stress responses between men and women should focus on gender differences.

7. Limitations and Future Work

On innovation, research based on the theory of relieving mental stress, using multiple linear regression model-building, reveals the forest park environment’s internal components of the recovery effect and the combination of the overall environment perception, for forest parks and update provides theoretical guidance basis. However, the study also has some limitations: (1) in terms of research methods, questionnaires are mainly used to investigate the subjective perception of the audience to obtain the analysis data. At present, some researchers have used blood pressure, electrocardiogram, brain waves and other routine body tests to obtain data, and some scholars have used medical test instruments to obtain data through facial muscles and an electroophthalmography tester. The research method of combining subjective perception and physiological response can more accurately obtain differences in the benefits of landscape environment recovery, which needs to be further improved in the subsequent research. (2) Previous studies have proven that the soundscape is one of the important design elements of the rehabilitation landscape and that the five-sense therapy of gardening is also a current popular form of the rehabilitation landscape. There are still some relative limitations in exploring the influence relationship between environmental, aesthetic and emotional function and the restorative effect, starting from the user’s psychophysical evaluation. (3) The outbreak of COVID-19 has had an impact on all industries and different disciplines. In the context of the new round of urban renewal, how forest parks can better help the public to alleviate the impact of the epidemic through their own advantages is the direction of further discussion. (4) In addition, human perception evaluation is a complex system, and given the limited sample data in this study, the conclusions obtained may be limited; therefore, in subsequent studies, comparisons between various city wooded-area parks have to be performed to affirm the well-known value of the corresponding conclusions.