Similarity Analysis And Simplification Of The Localization Spectral Cue In Sagittal Planes

Head-related transfer function(HRTF)contains a variety of spatial localization information,such as monaural information,Interaural Time Difference and Interaural Level Difference.For the sagittal plane of a particular angular distance of the space,the HRTF corresponding to these points on the sagittal plane has the same binaural localization information because the distance(time)difference on each sagittal plane is nearly constant,so the determination of the elevation angle in the sagittal planes mainly depends on the HRTF monaural information.In this paper,the similarity between spectral information of sagittal plane HRTFs with the same elevation angles is studied by using the correlation analysis and spectral distortion methods with reference to the median sagittal plane.It is convenient to use the binaural polar coordinate system to study the sagittal planes mentioned above,so we choose the CIPIC HRTF database for the similarity analysis.This database is currently the only public database using binaural polar coordinate system for measurement,so it is more easily to separate the data information of all sagittal planes.The results show that: in a certain low frequency range,the monaural information of HRTF on the lateral sagittal plane is highly similar to the monaural information of HRTF on the median sagittal plane;The similarity decreased gradually with the deviation of the sound source from the median plane.According to the above results,we propose simplified models of HRTF for the lateral sagittal plane.Based on the similarity between spectral information on median sagittal lateral sagittal planes,the HRTF amplitude spectrum of the median sagittal HRTF amplitude spectrum is used instead of the lateral sagittal target orientation.Furthermore,a series of psychoacoustic experiments are conducted to validate the simplified model.The experiment is divided into seven groups,including two modes of operation(static and dynamic virtual auditory playback),two HRTF data types(HRTF of KEMAR dummy and live man),three HRTF data properties(raw measurement data,simplified Model I and simplified Model II).0 ~ 12 kHz white noise is used in the experiment,and eight people with a certain experience participate the experiment.Finally,the effectiveness of the simplified model is evaluated by the in-head localization rate,the front-back confusion rate,the up-down confusion rate and the angle error.This study investigates the similarity of the localization information on the sagittal plane and helps to further understand the mechanism of sagittal plane localizaiton;On the other hand,this work proposes a simplified model of HRTF on the lateral sagittal plane which can be directly applied to practical applications related to virtual auditory reproduction.