Effects of response scale conversion and questionnaire configuration on soundscape assessment based on ISO/TS 12913-3

Soundscape evaluation commonly relies on Perceived Affective Quality (PAQ) questionnaires to translate subjective auditory experience into structured perceptual data. However, the influence of response scale format and PAQ questionnaire configuration on ISO-based soundscape analyses remains insufficiently examined. This study investigates how these methodological decisions affect both statistical outcomes and the soundscape circumplex representation defined in ISO/TS 12913-3. A field experiment was conducted across five heterogeneous university environments, involving 246 completed questionnaires. Four questionnaire versions were compared by combining two response scale formats (five-point ordinal versus continuous metric 0–100) and two PAQ configurations (four bipolar adjective pairs versus eight single attributes). Ordinal responses were converted into metric values using Snell’s latentscale transformation and a fixed-value mapping approach. The resulting datasets were analyzed using Mann–Whitney U tests, descriptive statistics, and kernel-density circumplex graphs. Snell’s conversion led to attribute-specific redistributions, notably affecting medians and kurtosis, whereas fixed-value mapping closely aligned with native metric responses. Questionnaire configuration exerted a systematic influence on perceptual outcomes: bipolar PAQs produced compact distributions concentrated in the Calm quadrant, while the eight-attribute configuration captured broader perceptual variability extending toward the Vibrant and Chaotic regions. The attributes Uneventful and Monotonous exhibited the highest distributional instability across configurations. The convergence between inferential statistics and circumplex representations reinforces the validity of the results. Overall, the findings demonstrate that response scale conversion and PAQ configuration critically shape ISO-based soundscape interpretations, providing methodological guidance for harmonizing PAQ applications in perceptual-acoustic research.