Spatial Comparison of Full Sphere Panning Methods

The goal of the thesis work is to compare different multi-channel panning methods for rendering an audio source in a 3D space, analysing the pros and the cons of the methods in terms of localization and certainty. The project has been realised at the University of Surrey, with the supervision of Prof. Enzo De Sena. The first chapter talks about the background of the research topic. As an introduction, all the phenomena that control auditory perception along horizontal and vertical planes are illustrated, with the following explanation of how panning works in terms of Inter Level Ratio and Time Difference between channels and the various techniques for reproducing these effects with microphones arrays. Then, different panning approaches that use these techniques are shown for the horizontal and vertical dimension, starting from the classic Stereo Configuration to the 3D methods as VBAP (Vector Base Amplitude Panning, by Pukki) or WFS (Wave-Field Synthesis). After this background part, an original panning approach for 3D space is presented. The method is called Hybrid cause combines Time Intensity Difference for the horizontal plane and Intensity Difference only for the vertical plane. The starting point is a previous work from Prof. Enzo De Sena about panning on the horizontal plane, a method that has been extended to the vertical plane in this thesis project. After the theoretical design of the method, an experiment with mainly trained listener participants is run to evaluate the Hybrid approach. The goal of the experiment has been to compare the performance of an existent method (VBAP) with different implementations of the Hybrid approach, in terms of Localization and Certainty of every answer. During the experiment, was asked to every subject to indicate the position of different sound events placed in different positions in front of them and to establish the degree of certainty of each answer. The details of the implementation and the results are presented in Chapters 4 and 5. At last, the conclusions of the work are presented.