Final Thesis

Development of a demonstration and evaluation tool for individualized binaural technology

Master Thesis of Doma, Shaimaa

The transfer function from an arbitrary source direction to the ear canal entrance is characterized by typical interactions with head, pinna and torso geometry. This highly individual filtering of sound is described by the head-related transfer function (HRTF) and is essential for a realistic spatial auditory reproduction. Obtaining individual HRTFs of high quality, however, requires specialized equipment that is not widely available. In some cases, it has shown to be particularly difficult, e.g. for children, whose movement during the measurement leads to inaccurate results. Individualized HRTFs offer a compromise by making modifications to a given non-individual HRTF set. Over the past years, various approaches have been discussed, such as the individualization of the Interaural Time Difference (ITD), frequency scaling or methods based on Principal Component Analysis (PCA). These methods use anthropometric dimensions to estimate a subject’s individual HRTF. The dimensions can, for instance, be obtained from 3D images generated by structured light scanners or magnetic resonance imaging (MRI). In this thesis, a tool is to be developed which allows for a direct auralization whilst manipulating the parameters of several of the aforementioned HRTF individualization methods. Using a set of exemplary virtual acoustic scenes, the user shall be able to modify a provided HRTF set. Applications of the tool comprise the subjective optimization and evaluation of HRTFs.