The new soundscape after the Covid-19 lockdown Katarina Paunović 1 , Branko Jakovljević 2 University of Belgrade, Faculty of Medicine, Institute of Hygiene and Medical Ecology Dr Subotića 8, 11000 Belgrade, Serbia Radmila Mirčić 3 University of Belgrade, Faculty of Medicine Dr Subotića 8, 11000 Belgrade, Serbia Dragan Pajić 4 , Milan Konatarević 5 Institute of Public Health of Belgrade Bulevar Despota Stefana 54a, 11000 Belgrade, Serbia

ABSTRACT We present a pilot study on the perception of noise and noise annoyance from various environmen- tal sources after the COVID-19 lockdown in Serbia. We used an online platform to conduct an anonymous survey on about 190 respondents aged 15 to 75 years from all over the country. After the lockdown, there was a significant increase in the proportion of respondents who were highly annoyed by noise from the typical environmental sources, such as road traffic, air traffic, industrial facilities, and construction works on the streets, compared to the time during the lockdown. At the same time, the proportion of respondents who were highly annoyed by the sirens of ambulance ve- hicles decreased significantly. However, the most annoying environmental sound during and after the lockdown was that emitted by the ambulance vehicles, which respondents described as “un- pleasant”, “horrifying” and “irritating”. The perception of the sounds of nature and church bells dropped significantly after the lockdown, whereas the perception of noise from the neighbors, household members, and indoor sources remained the same. In summary, after the lockdown, re- spondents perceive the new soundscape as louder, burdened with a cacophony of noises, and sub- sequently more annoying.

1. INTRODUCTION

The era of the COVID-19 pandemic has provoked many environmental changes. Scientific re- search across the globe report on the improvements in air quality, decrease in the emission of greenhouse gases, decrease in noise levels, reduction in water and soil pollution, etc. The restrictive

1 katarina.paunovic@med.bg.ac.rs

2 jakovljevic@dr.com

3 radmilamircic95@gmail.com

4 dragan.pajic@zdravlje.org.rs

5 milan.konatarevic@zdravlje.org.rs

anti-pandemic measures helped people struggle with the infection and had a positive effect on eco- systems and wildlife [1, 2].

Serbia enforced the state of emergency, commonly known as a national lockdown, from March 15th to May 6th, 2020 [3, 4]. The lockdown measures included the ban of all urban public and pri- vate transport, interregional transport, commercial and construction activities, sports, entertainment, educational activities, etc. Under the new circumstances, people perceived less noise from the typi- cal community sources and more noise from their neighbors and emergency vehicles [5]. Most peo- ple cherished the silence during the lockdown despite complaints about neighborhood noise and high annoyance from ambulance sirens [5].

Nevertheless, once the state of emergency was over, most measures became less restrictive, ex- cept for the ones related to closed spaces, occupational, educational, and hospital settings. People were no longer forced to stay and work from home, and they gradually resumed their usual activi- ties. The acoustic environment changed again, but this time for the worse, with dominant noises from the traffic, commercial, and industrial facilities. We hypothesize that the new soundscape after the lockdown affects people‟s perception of noise, which in turn leads to an increase in noise an- noyance from traffic or other community-related sources and/or a decrease in noise annoyance from neighborhood-related sources.

This pilot study compares the perception of noise and annoyance from various noise sources af- ter the lockdown with the respective parameters during the lockdown.

2. METHODS

The present study re-analyses our previously published data on the perception of noise and noise annoyance during the lockdown [5]. Now we compare the given parameters during the lockdown with the respective responses after the lockdown.

2.1. Sound pressure levels

Institute of Public Health of Belgrade, commissioned by the City Council for Environmental Protection, measures sound pressure levels regularly twice per year – in spring and autumn. The measurements are performed on 35 noise monitoring stations across the city. Microphones are placed at an average of 4 meters from the ground, depending on the surroundings, at least 3 meters away from sound-reflecting surfaces when possible. When reference conditions are not feasible, the tendency is to use flush-mounted microphone position with appropriate standard corrections. Mete- orological conditions are monitored and taken into consideration. Each measurement lasts for 24- hours, split into three referent time intervals: daytime (6 a.m. to 6 p.m.), evening (6 p.m. to 10 p.m.), and nighttime (10 p.m. to 6 a.m.). Average sound pressure levels are, therefore, presented as equivalent sound levels for daytime (Lday), evening (Levening), and night (Lnight). Measurements are performed in line with the national regulations [6] and EU Noise Directive [7].

We present the average, minimum, and maximum equivalent sound pressure levels (dBA) for the City of Belgrade available for spring 2020, autumn 2020, and spring 2021 to illustrate the trends during and after the lockdown.

2.2. Study participants

The online survey took place from January to March 2021 using Google Forms software. The authors shared the survey link through various social network platforms.

The anonymous questionnaire included one‟s age, gender, education level, perception of noise from various sources, and noise annoyance from noise during and after the lockdown.

Participants rated their perception of noise and noise annoyance on the 5-point verbal scales, graded as 0–„not at all‟, 1–„slightly‟, 2–„moderately‟, 3–„very‟, 4–„extremely‟. We merged the latter two categories to identify participants who are highly perceptive of noise and highly annoyed by each noise source. We estimated subjective noise sensitivity using a single question, on a numerical scale from 0–„not at all‟ to 10–„extremely‟. Highly noise-sensitive participants had scores above the median value.

2.3. Statistical analysis

We present descriptive statistics as mean values ± standard deviation (SD) for numeric variables or as percent (relative numbers) for categorical variables. We compared the proportions of highly perceptive and highly annoyed participants during and after the lockdown using McNemar‟s test for two related samples. We compared sound pressure levels at different seasons and mean scores for perception and annoyance during and after the lockdown using Wilcoxon signed ranks test for two related samples. Multiple logistic regression models were fitted to calculate odds ratios for high noise perception and high noise annoyance in relation to high noise sensitivity, adjusted for partici- pants‟ age, gender, and education level. Statistical analysis was performed using SPSS for Windows (Version 22.0, SPSS Inc. Chicago, IL). 3. RESULTS

Average equivalent sound pressure levels in Belgrade are presented in Table 1. Average sound pressure levels were significantly higher in autumn 2020 (at day and evening) and spring 2021 (at day, evening and night) in comparison to spring 2020 (Table 1).

Table 1: Equivalent sound pressure levels at day, evening, and night (dBA)

in spring 2020, autumn 2020, and spring 2021 in Belgrade

Time of day Parameters Season Spring 2020 Autumn 2020 Spring 2021 Day (6:00-18:00)

Mean±SD 60.2±6.0 61.5 ±6.0 * 63.2±6.4* Min - Max 47.5 - 70.1 48.2 - 70.9 46.0 - 71.9 Evening (18:00-22:00)

Mean±SD 59.1±6.8 60.6 ± 6.4* 62.8±6.2* Min - Max 44.7 - 69.7 48.5 - 70.5 46.2 - 76.7 Night (22:00-06:00)

Mean±SD 54.3±7.8 55.9 ± 7.6 57.2±6.8* Min - Max 35.8 - 65.6 39.4 - 72.2 36.4 - 67.9 * Significant difference from the respective time of day in spring 2020 (p<0.05)

SD – standard deviation; Min – minimum; Max – maximum

Among 187 study participants, most were women (82%), young to middle-aged (median age 30 years, range 15 to 75 years), with a university degree or higher education level (70%).

After the lockdown, participants‟ average perception scores for road traffic, air traffic, industrial facilities, and construction works on the streets increased significantly compared to the respective perception scores during the lockdown. In other words, participants more intensively perceived noise from these sources. At the same time, there was a significant decrease in the average percep- tion scores for the sounds from nature, church bells, and ambulance sirens after the lockdown, i.e. these sounds were less intensively perceived than during the lockdown (Table 2).

A verage perception scores by the source of noise during and after the lockdown are presented in Table 2.

Table 2: Average perception scores by the source of noise during and after the lockdown

Sourc e s of noise During the lockdown After the lockdown Ro a d traffic 1.9±0.9 2.7±1.3 * A i r t raffic 1.3±0.6 1.7±1.0 * Industri a l facilities 1.4±0.7 1.7±0.9 * Construc t ion works 1.8±1.1 2.4±1.2 * Home a p pliances 1.8±1.1 2.0±1.0 Ele v ators 1.5±0.9 1.6±0.9 ** Househol d members 2.1±1.1 2.1±1.1 Nei g hbors 2.1±1.1 2.2±1.1 Natu r e sounds 2.5±1.3 2.1±1.1 * Chu r ch bells 2.1±1.3 2.0±1.1 ** Ambu la nce sirens 2.9±1.5 2.7±1.3 ** * Highly significant difference from the average perception score during the lockdown (p<0.01)

** Significant difference from the average perception score during the lockdown (p<0.05) After the lockdown, one-third of participants were highly perceptive of noise from ambulance si- rens, and one-third was highly perceptive of road-traffic noise. One in five people were highly per- ceptive of noise from the construction works in the streets. Compared to the situation during the lockdown, the proportion of participants who were highly perceptive of road traffic noise, aircraft noise, and noise from industrial facilities increased significantly. At the same time, there was a sig- nificant decrease in the proportion of participants highly perceptive of the sounds from nature and church bells. About one-third of participants remained highly perceptive of noise from ambulance sirens after the lockdown (Figure 1).

The proportion of participants highly perceptive of noise from various sources during and after the lockdown is presented in Figure 1.

35%

Ambulance sirens

29%

22%

Nature sounds

12%

*

20%

Church bells

11%

*

12%

Household members

12%

12%

Neighbors

14%

9%

Construction works

21%

8%

Home appliances

9%

5%

Road traffic

29%

*

4%

Elevators

6%

3%

Industrial facilities

7%

*

2%

Air traffic

9%

*

0% 5% 10% 15% 20% 25% 30% 35% 40%

During the lockdown After the lockdown

Figure 1: Proportion of highly perceptive participants during and after the lockdown * Significant difference from the proportion of highly perceptive participants during the lockdown (p<0.05)

After the lockdown, participants‟ average annoyance scores for road traffic, air traffic, industrial facilities, and construction works on the streets increased significantly compared to the respective annoyance scores during the lockdown, meaning they were more annoyed by these sources after than during the lockdown. At the same time, participants‟ average annoyance scores for ambulance sirens decreased, implying that after the lockdown they were less annoyed by the sound of ambu- lance sirens than during the lockdown (Table 3).

A verage annoyance scores by the source of noise during and after the lockdown are presented in Table 3.

After the lockdown, one in ten participants was highly annoyed by road traffic noise, and noise from construction works in the streets. Compared to the situation during the lockdown, there was a significant increase in the proportion of participants highly annoyed by road traffic noise and a de- crease in the proportion of respondents highly annoyed by the ambulance sirens. However, one in four participants remained highly annoyed by the noise from ambulance sirens after the lockdown. The proportion of participants highly annoyed by their household members and neighbours, and other indoor and outdoor sources remained unchanged compared to the time during the lockdown (Figure 2).

Table 3: Average annoyance scores by the source of noise during and after the lockdown

Sources of noise During the lockdown After the lockdown Road traffic 1.6±1.0 2.0±1.2 * Air traffic 1.2±0.6 1.4±0.8 * Industrial facilities 1.3±0.8 1.5±0.9 * Construction works 1.7±1.1 2.0±1.2 * Home appliances 1.5±0.8 1.6±0.9 Elevators 1.4±0.8 1.4±0.8 Household members 1.6±0.9 1.7±1.0 Neighbors 1.9±1.1 1.9±1.1 Nature sounds 1.4±0.8 1.3±0.7 Church bells 1.4±0.9 1.4±0.8 Ambulance sirens 2.5±1.5 2.3±1.4 ** * Highly significant difference from the average annoyance score during the lockdown (p<0.01)

** Significant difference from the average annoyance score during the lockdown (p<0.05) The proportion of participants highly annoyed by noise from various sources during and after the lockdown is presented in Figure 2.

29%

Ambulance sirens

23%

*

11%

Neighbors

8%

9%

Construction works

12%

5%

Road traffic

13%

*

5%

Church bells

4%

5%

Household members

7%

4%

Home appliances

5%

4%

Elevators

3%

4%

Industrial facilities

6%

3%

Nature sounds

2%

2%

Air traffic

4%

0% 5% 10% 15% 20% 25% 30% 35%

During the lockdown After the lockdown

Figure 2: Proportion of highly annoyed participants during and after the lockdown * Significant difference from the proportion of highly annoyed participants during the lockdown (p<0.05)

Highly noise-sensitive participants were more likely to be highly perceptive of the following sounds after the lockdown: road traffic, ambulance sirens, church bells, and the sounds from nature. Highly noise-sensitive participants were also more likely to be highly annoyed by road traffic noise, aircraft noise, neighbors‟ noise, ambulance sirens, and church bells after the lockdown (data not shown). The association was independent of participants‟ age, gender, and education level.

3. DISCUSSION

The present study deals with the perception of noise and noise annoyance after the lockdown in Serbia. We also show noise levels in Belgrade in 2020 and 2021 to illustrate the trends during and after the lockdown. Globally, sound pressure levels reduced considerably after imposing lockdown restrictions on traffic and social events. Noise pollution was lower during the lockdown than at the same time before the pandemic in many urban areas around the world; for example, Dublin, Ireland [8], the Ruhr area, Germany [9], Milan, Italy [10], Montreal, Canada [11], Kanpur, India [12], and Barcelona, Spain [13]. The average decrease in noise levels ranged from 5 to 10 dBA.

Nevertheless, urban noise bounced back following the relaxation of the restrictive measures. In Montreal, Canada, sound pressure levels increased slowly after the lockdown and nearly reached the pre-lockdown levels [11]. In Barcelona, Spain, it took more time for sound intensity to recover to the pre-lockdown levels; noise levels increased faster in areas with dominant road traffic than in areas with tourism-related noise sources [13]. In Girona, Spain, noise increased quickly after the lockdown and reached levels even higher than the usual ones in the city [14].

In the authors‟ opinion, people tended to perceive the soundscape in three patterns during the lockdown. First, people clearly observed the reduction in sound levels outdoors and recognized the lack of specific noise sources in the environment [5, 15]. People appreciated a quieter urban envi- ronment and often described the new soundscape as good, excellent, and pleasant [5, 16]. Under the unique circumstances, the risk of sleep disturbances dropped substantially in some urban areas [12].

Second, people started hearing the sounds of nature. In other words, people were paying more at- tention to their surroundings, including the natural environments with its sound characteristics [17]. As pointed out previously, some natural sounds, such as birds singing, were observed as positive, while neighbors‟ animals were perceived as a nuisance [5]. The shift from anthropogenic to natural sound sources in the environment was proved through spectral sound analysis [18].

Third, people started perceiving the new community sounds more intensely during the lockdown, mostly the sounds of household members, home appliances, and neighbors [16]. People were par- ticularly annoyed by their neighbors‟ activities [5]. Noise annoyance by these sounds during the lockdown depended mainly on ones‟ personality traits, as well as on age, gender, and education [15, 16]. Furthermore, dwelling conditions, such as insulation measures, year of construction, apartment size, and crowdedness, mediated noise exposure and, thus, annoyance reactions [16]. Consequently, neighborhood noise provoked conflicts between the affected subjects. While before the lockdown, most official complaints involved traffic and construction works, complaints regarding neighbors were dominant during the lockdown [19].

When restrictions came to an end, people perceived the environment as bad or not good again [16]. In our study, participants became highly perceptive of road traffic, aircraft, noise from con- struction works and industrial activities after the lockdown. The perception of noise from the neigh- bors, household members, and indoor sources remained the same as during the lockdown. Again, after the lockdown, the most annoying environmental sound was that of the emergency vehicles‟ sirens. The proportion of people highly annoyed by ambulance sirens is almost twice as high as that

of people highly annoyed by road traffic noise. Such high annoyance prevalence (one in four per- sons) makes us suspect that this specific loud wining sound triggers tension, anxiety, and fear for one‟s health and existence even after the first wave of danger has ceased.

As could have been expected, the perception of the sounds of nature dropped significantly after the lockdown. Moreover, our participants particularly lamented “birds being gone”, „the loss of si- lence“, and were missing “the good old quiet days of the lockdown”. In Spain, people are reportedly in favor of maintaining the level of urban noise achieved during the lockdown in the future [16].

Belgian research shows that highly noise-sensitive people have been more concerned about envi- ronmental issues since the pandemic [17]. The presented study also points out the importance of noise sensitivity, which strongly affects one‟s perception of the soundscape and predicts annoyance. After the lockdown, highly noise-sensitive persons were more likely to be highly annoyed by road traffic, aircraft, neighbors, ambulance sirens, and church bells. We trust that noise sensitivity is a stable personality trait specifically related to several psychological effects of noise exposure [20].

The presented study has several limitations related to its‟ design and purposive selection of par- ticipants. Moreover, we failed to consider many participant-related factors, such as personality characteristics and stress levels, which would play a role in assessing the soundscapes during and after the lockdown. We could not control the noise exposure-related factors, including noise sources, individual indoor and outdoor noise levels, and mediating dwelling and neighborhood characteristics. Nevertheless, by comparing the attitudes to noise during and after the lockdown, we are confident that our observed patterns can be relevant to people under similar circumstances.

4. CONCLUSIONS

In summary, after the lockdown, road traffic and emergency vehicles were the most prevalent sources of noise annoyance. One in three persons remained highly perceptive of the sirens of ambu- lance vehicles, and one in four remained highly annoyed by this sound after the lockdown. 5. ACKNOWLEDGEMENTS

This research is financially supported by the Ministry of Education, Science and Technological De- velopment of the Republic of Serbia, Project No. 175078. 6. REFERENCES

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