Spatial audio methods are gaining a growing interest due to the spread of
immersive audio experiences and applications, such as virtual and augmented
reality. For these purposes, 3D audio signals are often acquired through arrays
of Ambisonics microphones, each comprising four capsules that decompose the
sound field in spherical harmonics. In this paper, we propose a dual quaternion
representation of the spatial sound field acquired through an array of two
First Order Ambisonics (FOA) microphones. The audio signals are encapsulated in
a dual quaternion that leverages quaternion algebra properties to exploit
correlations among them. This augmented representation with 6 degrees of
freedom (6DOF) involves a more accurate coverage of the sound field, resulting
in a more precise sound localization and a more immersive audio experience. We
evaluate our approach on a sound event localization and detection (SELD)
benchmark. We show that our dual quaternion SELD model with temporal
convolution blocks (DualQSELD-TCN) achieves better results with respect to real
and quaternion-valued baselines thanks to our augmented representation of the
sound field. Full code is available at:
https://github.com/ispamm/DualQSELD-TCN.Comment: Paper under consideration at Elsevier Pattern Recognition Letter