Evaluation of the Minimum Audible Angle on Horizontal Plane in 3rd order Ambisonic Spherical Playback System

Immersive audio technologies such as ambisonics are receiving increasing recognition as the range of the applications is widening. Decoding algorithms, beside accurate mathematical representation of the soundfield, consider the psychoacoustic phenomena in order to deliver more convincing listening experiences. Therefore, determining the parameters that describe the acuity of human auditory perception system can help, among others, in further optimization of the algorithms or picking the right playback system layout. The aim of the presented study is to evaluate the perceived spatial resolution within the 3rd order ambisonic speakers' playback system through determining the Minimum Audible Angle (MAA) parameter. Through the years, different researchers performed the MAA test with the use of the physical sound sources. In this paper the procedure is the same but with the use of the phantom sources encoded with the use of the ambisonic tools. Obtained results are compared with the reference. The experiment incorporated 2 different listening tests, where MAA was determined using two types of the signal samples: pure tones and Gaussian noise. The panel of subjects consisted consecutively of 7 and 5 experienced listeners. Analysis of the results is a base for further research focused on perception of the phantom sources produced in ambisonics.