Assessing soundscape: Comparison between in situ and laboratory methodologies

Abstract

The assessment of soundscape implies an interdisciplinary approach, where objective and subjective aspects are considered. For the subjective evaluation, in situ and laboratory methodologies are usually followed. Local observations allow the collection of information on the influence of different stimuli present in the environment, whereas laboratory tests present a determined quantity of controlled stimuli to the evaluator. The purpose of this work is to compare results from the different methodologies in order to understand their strengths and their weaknesses. Three urban parks in the city of Lisbon, Portugal, were evaluated. Fragments of binaural sound recordings collected in the parkswere used in laboratory tests to compare with the responses in situ and of expert and nonexpert listeners. Statistically significant differences were found in several of the perceptual attributes under observation, which led to variation in the results of the main model's components. The sound environmentswere found to be more pleasant and uneventful in situ than in the laboratory, a phenomenon possibly due to the influence of other stimuli such as visual in the process of assessment. The in situ tests allow a systemic and holistic evaluation of the environment under study, whereas the laboratory tests allow a specific and tightly targeted analysis of different component sound events. Therefore, the two methodologies can be useful in soundscape assessment depending on the specific application and needs. No differences were found in the assessment made by either experts or nonexperts.