SOUNDSCAPE MAPPING OF AGODI PARK AND GARDENS, IBADAN SOUTHWESTERN NIGERIA

This study provides contextual evidence on recreational noise exposure in a typical Nigerian urban park. It investigated perceived sonic characteristics as well as the spatial noise variations across Agodi Park and Gardens in the city of Ibadan, Oyo State, Nigeria. Integration of noise mapping and soundscape methods was used to understand the nature of noise being generated in this outdoor setting. Sound Pressure Level (SPL) was used to obtain data from nine major locations within the park. Using a non-probabilistic method of sampling, fifty respondents


Urban parks and gardens are examples of urban open spaces and they provide multiple
services to the ecosystem generally. Urban open spaces exist on different scales (residential, neighborhood, and national), and their ownership can be either public or private. They can also be either free or fee-based (Ajayi & Amole, 2019). In terms of spatial configuration, some can be formal (purposely designed), while some are organic (informal) in nature. Out of the diverse typologies of urban open spaces; parks and gardens are the most popular globally (Stanley et al., 2012). Evidence from literature shows that parks and gardens are classified according to size, geographical location, target population, types of facilities, and the extent of naturalness of the site (Ajayi & Amole, 2019;Stanley et al., 2012;Bryne & Sipe, 2010). National Park, Urban Park, Community Park, District Parks as well as Pocket Parks are examples in existence. Apart from being pivotal in mitigating the effects of climate change, urban parks are also used by residents for leisure, tourism, cultural education, aesthetic appreciation, and spiritual needs (Gómez-Baggethun & Barton, 2013). Urban residents around the world express a desire for contact with nature and one another, including attractive environments, and recreational and play areas (Matsuoka & Kaplan, 2008). From the health perspective, parks and gardens have been reported to influence residents' health by encouraging health-promoting activities to take place. By this way, the availability and utilization of urban parks are associated with better health and quality of life of urban dwellers (Hartig et al., 2014;Ord, 2013;Lachowycz, 2013).
Individuals living in areas that lack urban parks may be more vulnerable to the negative impacts of stressful life events because they have less opportunities for nature-based coping strategies compared to individuals living in areas with abundant green spaces ( Van den Berg et al., 2010). There is a compelling accumulation of evidence from a large number of studies that indicates a positive association between exposure to urban open space(s) and stress reduction (WHO, 2016;Hatrig et al., 2014;Hughes, 2014). Benefits are reported to include enhancement of mood, concentration, self-discipline, and reduction of physiological stress (Hughes, 2014). Although parks and gardens are preferred destinations for various physical and social activities, they can also be potential sources of urban noise generation, thus reducing the restorative impacts generated by their natural environments in urban parks.
Urban parks are usually surrounded by busy streets, commercial buildings, and areas of high noise levels due to human activities and heavy traffic. Cao & Hsu (2021) affirmed that stress restorative benefits of urban parks may be compromised by overexposure to noise, which can have a negative impact on human health. It therefore goes without saying that patrons of urban parks might be denied the benefits of open space utilization if the noise level is beyond acceptable limits. A previous study opines that when urban parks are properly designed, they muffle urban noise pollution and can also provide relatively quiet areas to get away from the hustle and bustle of city lives (Lee et al., 2019). Ozdemir et al. (2014) defines noise as the level of sound which exceeds the acceptable level and creates annoyance, therefore the perception of acoustic environment by humans is important. In the United States, a recent noise survey across 251 sites in 66 National Parks indicated that recreational noise was audible in 37% of recording (Buxton et al., 2019). The composition of urban noise is complex, due to a wide range of sounds originated from different sources, such as transport (road traffic, aircraft and railway noise), commercial and entertainment activities (Gagliano et al., 2020). Evidence reporting the impact of noise on human health is accumulating (Douglas & Murphy, 2016;Meyer et al., 2017). A World Health Organization report in 2011 classified noise as the third most hazardous type of pollution in cities after air and water. Consequently, noise exposure in urban centers deserves better attention than it is currently being given because findings from a World Health Organization study (2018) showed that globally, 466 million people are suffering from disabling hearing loss and in 2050 it is estimated to amounting a total of about 900 million people i.e., 1 in every 10 people will be affected.
According to Guski et al. (2017), environmental noise annoyance is a retrospective judgment comprising of previous experiences with a noise source over a particular period, and there are three elements to the noise annoyance response: a frequently repeated disturbance caused by noise, an attitudinal/emotional response, and cognitive response. Parks and outdoor areas offer a unique opportunity to conserve acoustic environments dominated by biophonic and geophonic sounds (Dumyahn & Pijanowski, 2011). Studies on outdoor soundscape have categorized acoustic environments into three categories; anthrophony, biophony, and geophony (Cao & Hsu, 2021;Buxton et al., 2019). Anthrophony sounds are generated from humans or man-made objects. The sound emanating from natural living sources are called biophony, while sounds produced by the natural non-living (geophysical) environment are called geophony (Li et al., 2018). In the United States, a study to understand the relationship between humans and sounds from biological, geophysical, and anthropogenic sources in parks found a clear preference for biophony and geophony and an aversion to anthrophony (Li et al., 2018).
The sonic environment although invisible, is a vital component of the urban environment that is influenced by population density and social contacts driven by urbanization. To stem the detrimental effects of noise pollution, government and agencies enact regulatory policies at various administrative levels. The standard approach for noise regulation is to set maximum thresholds for Sound Power Level (SPL) and to require mitigation activities when the limits are surpassed. The World Health Organization (WHO) recommends avoiding exposure to noise levels over 53 decibels. There are maximum acceptable noise levels (continuous equivalent sound levels-LAeq) for different environments recommended by the

Environmental, Health, and Safety (EHS) Guidelines (2007) of the World Bank Group
International Finance Corporation (IFC) (www.ifc.org/ehsguidelines). In the USA, for instance, the Noise Control Act was enacted by Congress in 1972 and amended in 1978; later, the primary responsibility for regulating noise was delegated to state and local governments (Asdrubali, 2014). Likewise, in Nigeria, the maximum permissible noise limits (LAeq) for various land uses are also enumerated in the Nigerian National Environmental Standards and Regulations Enforcement Agency (NESREA) Noise Standards and Control guidelines for community noise (Alani et al., 2020).
Noise maps, which are graphical representation of the noise levels are used frequently as a guide in urban noise management (Antonio et al., 2020;Alam et al., 2017). It can also help in the estimation of environmental noise exposure in a particular location as well as a tool for designing noise-control plans. Thus, noise maps serve as a useful strategic tool for environmental management decisions and environmental planning (Manojkumar et al., 2019).
Soundscape analysis is one of the methods used in noise studies, and it consists of a set of audio recordings of an environment together with the perception of a group of people captured with the help of a questionnaire (Lee et al., 2019). Globally, studies have measured, predicted, and mapped noise levels in urban cities (Alam et al., 2017;Margaritis & Kang, 2017;Manojkumar et al., 2019), while some used participatory mapping techniques (D'Hondt et al., 2013;Guillaume et al., 2016). In the Nigerian context, considerable research work has been done in this regard, for instance, Alani et al. (2020) assessed spatial variation of noise levels within a section of the Festac residential area in Lagos and concluded that the highest mean noise levels occurred where a bus park is present.
In addition, Oyedepo (2012) reported that the daily noise levels in Abuja municipality were above the recommended tolerable values by the World Health Organization. While the findings from these studies are pertinent to mitigating the noise menace in our cities, the absence of specific and significant studies on recreational/leisure noise pollution in the Nigerian context validated this study.
Moreover, the European Environmental Agency (EEA) in the Good Practice Guide on Recreational Centers (2018), opined that a holistic method that combines environmental noise policy using noise mapping with the soundscape approach is best suited for noise planning, however, studies using this method for recreation planning are sparse in Nigeria. It is therefore important to analyze the perceived sonic characteristics of Agodi Park and Gardens, examine and map the spatial recreational noise variations across locations of the park, and the significant difference between the daytime noise levels and night-time noise levels.

Study area
Geographically, Ibadan city is in Oyo state, in the present south-western geo-political region of Nigeria (see Figure 1). It has served as the capital of Oyo State since 1967 and is currently  was used to obtain the instantaneous sound pressure level, the minimum SPL, the maximum SPL, and the continuous equivalent SPL at the nine locations. This information along with GPS locations was written to log files which were then used to generate noise maps. The SPL was placed at a height of 1.2 m above ground level to exclude reflections from the ground and pointed at the suspected noise source at a distance not less than 1 meter away from any reflecting object. In a related study by Lee et al. (2019), over 7 hours of environmental noise data were collected using the smartphone method, and accuracy of ±0.7 dB for 99.7% of the measurements was recorded. This range of accuracy validates the smartphone for measuring the sonic environment. In this current study, a-weighted continuous equivalent sound level (LA eq), instantaneous minimum (LA min), and maximum (LA max), sound level measurements were taken for a period of 5 minutes per location during the weekend. This procedure was repeated in the morning and evening because the park was usually busy during these periods and are fairly representative of daily recreational noise variations within the study area.

Socio-demographic characteristics of respondents
The results of the distribution as presented in Table 1 show that 44% of the respondents were male, while 56% were female. In addition, half of the respondents (50%) had tertiary education and only 4% had lower than secondary education. Therefore, the respondents were considered educated generally enough to understand the essence of the survey. It was also observed that majority of the respondents were aged above 18 years. The distribution of the respondents shows that majority were single (62%), and 42% of the total respondents came to the park for relaxation purpose. Table 1.

Respondents' perceptions of recreational noise in Agodi Park and Gardens
The study highlighted and segmented the perceived soundscape characteristics of the park by users into three categories. Perceptions of noise emanating from natural and non-living sources are referred to as geophony sound. Biophony sound is the second category, consisting of sounds generated from natural and living sources, while manmade source (anthrophony) is the third category. The results of the perceived geophony characteristics as depicted in Table   2, highlight that sounds from the natural and non-living sources in the park were soothing and not distressful in nature. The geophonic factor with the highest value was the flowing water with a mean weighted value of 2.32; followed by rainfall (2.10) and humming of the wind (2.08). The soundscape of a park is incomplete without the biophony sources of sound as seen in Table 2. Given the fact that Agodi Parks and Gardens has natural green vegetation and some elements of thick forest, animals can also be found in the environment.
Although most respondents were not perturbed by the biophonic sounds, the loudest came from chirping birds/ insects (2.14). However, the sound of music from events (amplified sounds) was the major source of anthrophony sound in the park. The respondents asserted that the music from events (amplified sounds) is often loud but not uncomfortable with the MWV of (3.58). Also, sound from electric power generator was another major source of sound (3.02). This finding is a reflection of the current situation in Nigeria; the country is faced with severe power supply shortage and most households and business are powered by generators.
This result also corroborates the findings of Alani et al. (2020) that electric power generators are the major sources of noise pollution reported by residents of Festac Town, Lagos, Nigeria.
Another source of sound is sporting activities within the area of study. Sport attracts crowds and amusement, and since people tend to become excited when engaging in competition, noise emanates. Furthermore, background noise (2.58) and traffic (2.56) along the major roads around the park also contribute to the high degree of the noise in the park.  Table 3 reports the perceived level of desirability of the soundscape in the study area, and also reports the sum of weighted value (SWV) and mean weighted value (MWV). The table shows that the sound produced from power generators had the least level of desirability among soundscape characteristics in Agodi Park and Gardens. This was affirmed by the percentages of respondents who claimed not to be pleased with this type of sound with a MWV of (1.4).

Respondents' level of desirability of the soundscape in Agodi Park and Gardens
On the other hand, sound produced from the stream (flowing water) across the park was ranked as the most desired of the 22 soundscape characteristics with a MWV of (2.68). The respondents affirmed that the music from events (amplified sounds) is often loud but desirable with the MWV of (2.66) which was ranked as second. Also, sound produced from singing birds was another well desired soundscape characteristic in the study area with an MWV of (2.64).

Daytime sound level
As presented in Figure 6 and Table 4, the maximum level of sound was recorded around the ice-cream spot/ walkway with a range between 105dBA -68dBA. The high background noise in this section of the study area might be associated with the unpleasant noise originating from the mobile power generating set in this vicinity. This could unsettle urban park users or lead to displeasure or might affect their health and psychological well-being. An earlier study exerted 60dBA as the exterior limit for urban parks and open spaces, beyond which annoyance and hearing impairment are inevitable (Dhananjay & Prashant 2007). Furthermore, in the bar and its surroundings, an average of 68dBA was measured, while the games area had an average of 80dBA, and 77dBA was the average sound level around the restaurant. Other areas around the swimming pool also had 77dBA in the level of noise exposure, paint ball arena (73dBA), car park (73dBA), and the open field was (71dBA).   Further investigation showed some variations in the measured noise levels in the evening (see Table 5 and Figure 7). This might be explained by the increment in the number of patrons as the night approaches. Most users often patronize recreation centers in the evening after daytime activities come to an end. The maximum level of sound recorded in the study area was at the parking lots, which might be due to the elevated vehicular traffic occasioned by the ingress and egress of users. It was also observed that the volume of traffic around adjoining roads increased in the evening and added to the noise filtering into the study area. This result is as expected, and similar to the findings of past studies (Oyedepo & Saadu, 2010;Lee et al., 2019). The ice-cream spot had an average of 91dBA sound level, while areas around the parking lots generated an average of 87dBA and the open field recorded an average of 82dBA.  The result of the inferential test of difference between the evening and morning indicates that there is a significant difference between the sound levels in the evening and morning (see Table 7). The mean difference indicated that evening sound levels are higher than the morning sound levels with a mean difference of 4.7778. The test statistics show that the difference is statistically significant at 5% level of significance (-11.733). This result implies that at the gardens, activities in the evening generated more sounds than in the morning. Table 7. should be considered in the design of future urban parks as they would go a long way in improving and enhancing the quality of perceived user's comfort. Urban Park administrators can use the information from noise maps to inform urban park users on the noise levels in different locations in order to help users navigate the park according to their moods and purpose of visit, besides maximizing the benefits of their experience at urban parks.

CONFLICT OF INTEREST
The authors declare no conflict of interest in this study.

ACKNOWLEDGEMENT
This research was self-sponsored and no form of aid nor specific grants was solicited or received from any funding agency in the private, non-governmental or public sectors locally and internationally. The authors wish to express profound gratitude to the staff and management of Agodi Parks and Gardens, Ibadan, Oyo State, Nigeria for their commitments, involvements, and support during data collection.