AES 5th International Conference on Automotive Audio

The loudspeaker configuration in a car is far from a conventional stereophonic one. The aim of this study was to evaluate the consequences of such an unusual configuration on the perception of the localisation of virtual sound sources. Experiments on the directional perception of virtual sources in an automotive environment were performed using conventional loudspeaker configurations. The sources, consisting of broadband pink noise bursts, were laterally spatialised using the Virtual Based Amplitude Panning (VBAP) method. Participants were asked to point their nose in the direction of the perceived sound source. Their head movements were recorded by a headtracker. The differences between the perceived directions and those predicted by the VBAP method in a classical stereo configuration were measured. In addition, several models of azimuth perception were compared with the experimental data. An extended energy vector model, taking into account the precedence effect, gave results in agreement with the experimental data. The model inputs are the relative position, time delay and level of each loudspeaker. This model could be used as a tool for assessing spatial restitution, loudspeaker implementation and audio tuning.

This paper investigates the perceived spatial extent of a local active noise control (ANC) system for different types of disturbances. Several publications have determined size and shape of the zone of quiet for various arrangements, primarily for pure-tone diffuse sound fields, through analytical and numerical methods. However, these studies have often overlooked human perception, focusing solely on technical properties. Therefore, a listening experiment has been conducted to determine the perceived size of the zone of comfort in a scenario close to reality, using an active headrest setup. Several operational frequency limits for different types and directions of broadband disturbances are examined. Within this experiment, lateral transitions to the front and head rotations at the target position have been considered. Statistically consolidated subjective ratings exhibit limits of around 2 cm to 4 cm for lateral transitions, with an expected decrease towards higher frequencies. When comparing participants’ answers to measurements, the majority of the median responses converge at a point with loudness reduction of 20%. The rotational limits of 7° to 15° are not as dependent on frequency, but rather on the distinct perception of the secondary sources and the loudness reduction as well.

This paper presents a synthesis of research spanning eight decades, investigating the relationship between auditory spatial perception and the effects of masking noise. Drawing from studies in psychoacoustics, it examines how different characteristics of masking noise affect fundamental auditory experiences such as sound localization, echo suppression, precedence effect, and similar phenomena.

Despite the extensive research, the practical application of these findings in audio products engineering (such as automotive sound systems) remains limited. Incorporating these scholarly insights into practical use could improve algorithms for spatial sound processing. Understanding the implications outlined in these studies is crucial for refining immersive sound reproduction and implementing new spatial audio formats into consumer devices.

The challenges posed by noise, especially in vehicles, emphasize the importance of applying prior research to enhance the user experience. This review highlights the need for understanding and applying insights from previous studies to improve the quality of experience of consumer audio devices and systems.