3D Microphone Array Comparison Part 2: Elicitation of Salient Perceptual Attributes

The growing adoption of three-dimensional (3D) audio technologies has driven the development of a wide range of microphone array techniques; however, perceptual differences between them remain insufficiently understood and require systematic investigation. This study reports a subjective experiment comparing four 3D array configurations (OCT-3D, 2L-Cube, and PCMA-3D with 0m and 1 m vertical spacings) using a 5.0.4 playback system. Excerpts of various musical recordings simultaneously made using the arrays were evaluated from three listening positions (centre, left, back) through elicitation and audibility grading tests. Results identified perceptual differences in conventional spatial and tonal attributes, but showed that their audibility varied considerably with sound source and listening position. Differences in spatial attributes such as listener envelopment (LEV) and apparent source width (ASW) were audible across most conditions, whereas attributes related to sound image location and stability, such as localisability, were more prominent for single sources and off-centre positions. Vertical image spread was salient only for pipe organ and a five-voice a cappella ensemble. Tonal attributes such as clarity, fullness, and brightness were particularly salient off-centre. These findings lay the foundation for future research on their relationship to listener preference and the development of 3D recording quality models.