Validating Thai translations of perceptual soundscape attributes: A non-Procrustean approach with a Procrustes projection

Abstract

Measurement of a psychological construct across populations without a common linguistic medium often necessitates the development of multiple translations of the psychometric tool across multiple languages, dialects, or other population-specific variations. In this follow-up (Stage 2) study, a listening test using a shared set of 27 stimuli from the Soundscape Attribute Translation Project (SATP) was conducted with Thai-speaking participants using the set of Thai translations of the eight perceptual affective quality (PAQ) descriptors selected in earlier (Stage 1) work through a structured evaluation questionnaire. Principal component analysis was performed on the listening test data to obtain a rank-two reduction of the responses with maximal explained variance. In order to align the principal component space to the two-dimensional circumplex space, this work presents a simple and numerically stable method based on the orthogonal Procrustes projection, to find the optimal two-dimensional orthogonal transform that aligns the first two principal components with the axes corresponding to Pleasantness and Eventfulness as defined in ISO/TS 12913-3:2019. Analysis of the listening test responses indicated good to excellent interrater reliability, reflecting the general comprehensibility of the translations to laypersons. Subsequent analyses yielded a two-dimensional projection with ▪ explained variance and near-perfect alignment of the composite Pleasantness and Eventfulness axes. Angular locations of the individual translated PAQs are located within ▪ of their theoretically ideal locations and preserve angular ordering, albeit with imperfect equiangularity. Cross-analysis against the results from Stage 1 showed that the structured evaluation may be partially useful in anticipating potential imperfections of the PAQ translations and their angular locations in Stage 2.