Sound image design in the elevation angle based on parametric head-related transfer function for 5.1 multichannel audio

Recently, with the development of image technology, multichannel audio that can reproduce highly realistic sound field has attracted attention. In particular, 5.1 multichannel audio has become the mainstream broadcast system for current TV programs and movies. However, it cannot design a sound image in the elevation angle because the loudspeakers are located only on the horizontal plane. To solve this problem, we propose a method of designing a sound image in the elevation angle for 5.1 multichannel audio. In the proposed method, we utilize a parametric Head-Related Transfer Function (HRTF) imitating the envelope of real HRTF. In addition, crosstalk is eliminated by designing a multichannel inverse system based on multi-input / output inverse theorem (MINT) for 5.1 multichannel audio. In the objective evaluation experiment, we compared the localization directions of the actual sound source and the sound image constructed based on the proposed method. From the experimental result, we confirmed that the proposed method can design a sound image closer to the actual sound source in both azimuth and elevation directions compared to the conventional 5.1 multichannel audio.