Off-Center Listening with Third-Order Ambisonics: Dependence of Perceived Source Direction on Signal Type

In multichannel reproduction, listening at off-center positions involves differences in loudspeaker signal arrival times, meaning that the precedence effect is an important factor in localization. Given that the type of signal is known to affect elements of the precedence effect, there is a need to understand the implications regarding the perceived auditory source image angle and the prediction thereof. In this paper the results of a localization experiment for off-center listening positions are presented, in which subjects were tested for transient and non-transient noise signals using third-order Ambisonics. These results are compared to those obtained with several prediction models, including an extended version of the energy vector model that incorporates the precedence effect. Compared to two binaural models, the extended vector model is shown to provide the best predictions over all conditions. The results confirm that the type of signal must be taken into account in predictive modelling. Furthermore, the extended energy vector exhibits about 50% less error than the standard energy vector.