Auditory Pleasantness. Methodological Considerations in the Application of Psychophysical Scaling Methods for Sound Quality Evaluation

The thesis addresses various methodological issues relevant in the application of psychological methods for measuring the pleasantness of meaningful complex sounds. In the theoretical part, the notion of sound quality is first introduced and the theoretical framework for auditory pleasantness is outlined. Further, an overview of psychometric methods commonly used in the field of sound quality evaluation is presented. The empirical part concerns primarily a comparison of frequently used psychophysical methods, including both direct scaling procedures and indirect scaling according to "Thurstone's Law of Comparative Judgment." With respect to the latter, the particular focus is on the suitability of the method in terms of the model fit of a paired comparison scale. In the direct scaling approach, several psychophysical issues are addressed such as the concordance of magnitude estimation and category scaling, appropriate anchoring of the category scale, and the impact of the immediate stimulus context on category ratings. In addition, the latter issue is also studied in the Semantic Differential Technique; consequences of varying serial contexts are examined with regard to possible profile shifts on the one hand, and the impact on the reliability and sensitivity of the measurements on the other.