Compatibility of quantitative and qualitative data-collection protocols for urban soundscape evaluation

Abstract

This study investigates the compatibility of soundscape evaluation results based on the data-collection protocols proposed in ISO 12913-2, Method A (questionnaire), Method B (questionnaire and open-answer), and Method C (narrative interview), as well as guidelines for evaluating urban soundscapes. We assessed the soundscapes of 10 multi-functional sites in an urban environment through the responses of 50 participants to questions on sound source identification, perceived affective quality, and overall quality. Using virtual reality technology, we reproduced a laboratory environment similar to the actual assessment sites. The responses to sound source identification were similar for each protocol. Regarding perceived affective quality, the “pleasantness-eventfulness model” derived from Method A was also found in the text-mining results of Methods B and C; additional emotional responses were discovered. Regarding overall quality, the preference for each assessment site was similar for each protocol. Method C revealed the influence of non-acoustic factors on soundscape perception. The quantitative data protocol was appropriate for a large group and for deriving a generalized model, whereas the qualitative data protocol was effective for small groups or an in-depth analysis of certain sites. The findings of this study are useful for assessing urban soundscapes and informing urban planning.