SUBJECTIVE ASSESSMENT OF AURALIZATIONS CREATED BY MEANS OF GEOMETRICAL ACOUSTICS AND FINITE ELEMENT NUMERICAL METHODS

摘要

This paper presents a subjective assessment of auralizations created by means of numerical methods such as Geometrical Acoustics (GA) and Finite Elements Method (FEM). A subjective test was implemented in order to evaluate the virtual sound environments created for a meeting room at the Institute of Sound and Vibration Research (ISVR), in the University of Southampton, UK. The auralizations were reproduced in a binaural 3D system based on Optimal Source Distribution (OPSODIS). The perceptual parameters assessed in the subjective test were source localization, reverberation or spatiality, warmth and brightness. Three sound sources were used to create the auralizations: a human voice (speech), a percussion instrument and a wind instrument, all of them recorded in a recording studio. Three groups of auralizations were created, the first two using the following numerical approaches: GA and the combination of GA and FEM. The third group of auralizations was created by means of Binaural Impulse Responses (BIR) measurements. A comparison between the auralizations created using the numerical approaches was carried out having as a reference the auralizations obtained by means of BIR measurements. The reproduction system was located in a controlled environment and the evaluation scale was established according to the recommendations of the ITU-R BS.562-3, 1990. The statistics results indicated that the auralizations created using a hybrid approach presented more similarity for all the perceptual parameters in comparison with the auralizations created with only GA.