The Method of Soundscape Naturalness Curves in the Evaluation of Mountain Trails of Diversified Anthropopressure—Case Study of Korona Beskidów Polskich

Sound in the landscape is an element of the multisensory experience of the environment. In areas that are naturally valuable and additionally used for tourism, the quality of this element is much more important than in urban areas. The aim of the study was to assess the soundscape diversity of mountain trails included in the Crown of the Polish Beskids (Korona Beskidów Polskich). Two methods were used in the study: The first was sound intensity measurement using a sonometer, which provided information on the physical aspect of the landscape. The second method involved recording all sounds divided into two basic categories: anthropogenic and natural. These results made it possible to propose a new method for assessing the naturalness of the soundscape by plotting naturalness curves. In contrast to frequently used survey-based methods, in this method we minimise subjectivity, which is mainly due to the different perceptions of sounds by the assessors. Given how many psychophysical aspects can affect the reception and perception of sounds, the method of naturalness curves allows for a universal assessment of landscape quality. On all the mountain trails surveyed, the average sound intensity values exceeded 40 dB, which the authors considered to be borderline for areas of natural value and recreational use. In the study area, the influence of anthropopression on soundscape formation was found to be diverse and dependent on many factors. However, there was no clear evidence that tourism was the main negative influence. The plotted naturalness curves showed a large variation between trails, but not all trails showed a correlation between this parameter and the number of tourists on the trail.