## 1 Introduction  
Binaural audio systems are used to create an immersive and realistic listening experience, providing listeners with a sense of spatial presence and directionality. With the rise of virtual and augmented reality technologies (VR and AR), binaural audio systems have become even more significant, as they play a crucial role in creating a convincing sensory experience [1]. Binaural audio uses Head-Related Transfer Functions (HRTF), which are essential for localizing sound in space and creating a sense of spatial awareness [2]. In virtual and augmented reality, binaural audio systems are used to create a realistic soundscape that matches the user's visual environment, providing a more immersive and engaging experience compared to using only visual cues [3]. From gaming and entertainment [4] or medicine [5] to education and training [6], binaural audio systems and spatial audio are revolutionizing the way we interact with virtual and augmented environments.  
While generic HRTFs have been widely used in the field of spatial audio for creating a more accurate VR/AR experience [7], individual or personal HRTFs have the potential to personalize the experience even more. Furthermore, the use of generic HRTF can potentially lead to limitations in 3D audio perception in VR [8]. One of the potential principal benefits of utilizing individual HRTF as opposed to generic HRTF is the superior localization of sound sources within the frontal hemisphere, which may result in a higher degree of precision when employing an individual HRTF set that has been measured for a particular listener [9].  
The acquisition of individual HRTF for a particular person needs to be performed using one of the many methods and measurement setups available [10]. Acquiring individual HRTF typically requires multiple exponential sweeps that employ a circular arc segment comprising many loudspeakers placed in an anechoic chamber. The arc can be maneuvered around a fixed central point where the subject is positioned. The subject wears a pair of in-ear microphones to measure their individual HRTF using such a setup [11; 12; 13; 14]. Although the described conventional method of acquiring individual HRTF is still prevalent, recent years have seen the development of novel approaches that enable the acquisition of individual HRTF for a broader range of users without the need for complex measurement setups or an anechoic chamber. These new methods include techniques such as 3D scanning and modeling of individuals through structured-light/3D scanners or high-resolution pictures/video footage [15; 16; 17]. Another group of methods uses a single-speaker system placed in a typical room, and the subject wears a head-tracking unit equipped with Inertial Measurement Unit (IMU) sensors, implemented as a dedicated head-tracking unit or a smartphone [18; 19; 20]. For the purpose of this research, the methodology described in [18; 21] was used to obtain individual HRTF for the subjects who took part in experimental measurements.  
The primary objective of this study was to conduct experiments designed to test the hypothesis that the utilization of individual HRTF enhances the accuracy of localization of virtual sound sources, thus providing a more realistic and natural experience for the users compared to the situation when generic HRTF or the individual HRTF of another person are used. For this purpose, a novel methodology has been implemented for experiments that allow the hypothesis to be tested in highly dynamic virtual scenarios that emulate both real-life environments and virtual ones.  
The presented novel methodology was also used to confirm that the localization accuracy in the horizontal plane will not be substantially affected by using non-individual HRTF instead of individual ones due to more robust additional interaural time and intensity difference cues, whereas the accuracy in the vertical plane will be significantly improved if an individual HRTF set is used in binaural synthesis.