Efficient Phantom Source Widening and Diffuseness in Ambisonics

Object-based spatial audio considers virtual sound sources having a width/diffuseness parameter. This parameter aims at controlling the perceived width or diffuseness of the auditory object, or phantom source, created by the renderer. Width/diffuseness provides an important salience parameter that is independent of perceived direction and timbre. A highly efficient sparse filter structure for two-channel stereophony was described and tested recently, but it becomes ineffective for most parts of a large audience. This paper presents phantom source width/diffuseness control for Ambisonics. The new approach is a remarkably elegant application of the previously described stereo phantom source widening on Ambisonics. Compared with former experimental data, our experiments show a greater freedom of increasing the width and widening that works for a larger listening area