Augmented Intensity Vectors for Direction of Arrival Estimation in the Spherical Harmonic Domain

Abstract

Abstract-Pseudointensity vectors (PIVs) provide a means of Direction of Arrival (DOA) estimation for Spherical Microphone Arrays (SMAs) using only the zeroth and the first-order spherical harmonics. An Augmented Intensity Vector (AIV) is proposed which improves the accuracy of PIVs by exploiting higher order spherical harmonics. We compared DOA estimation using our proposed AIVs against PIVs, Steered Response Power (SRP) and subspace methods where the number of sources, their angular separation, the reverberation time of the room and the sensor noise level are varied. The results show that the proposed approach outperforms the baseline methods and performs at least as accurately as the state-of-the-art method with strong robustness to reverberation, sensor noise and number of sources. In the single and multiple source scenarios tested, which include realistic levels of reverberation and noise, the proposed method had average error of 1.5°and 2°, respectively.

CRNN-Based Multiple DoA Estimation Using Acoustic Intensity Features for Ambisonics Recordings

“…Another set of methods exploit the sound field characteristics: they mainly rely on the estimation of the acoustic intensity vector, which represents the flow of energy in each frequency band and provides an estimate of the source DoAs [9], [21], [22]. However, in the presence of noise and reverberation, the accuracies of all the aforementioned methods decrease dramatically [10], [23].…”

Spatial sound intensity vectors in spherical harmonic domain

“…6 To improve the accuracy of DOA estimation, an augmented intensity vector is proposed by exploiting higher order spherical harmonics. 7 All the applications mentioned above are based on sound intensity at a single point or several points, but these applications can be extended and facilitated by using spatial sound intensity vectors. For example, sound intensity based reproduction can be realized over space instead of at a single point using spatial intensity matching so that the original sound can be reproduced over a large region for more listeners.…”

Evaluation and Comparison of Three Source Direction-of-Arrival Estimators Using Relative Harmonic Coefficients

“…Alternatively, this paper presents a new solution to address the above distance-based DOA estimator in (12) using an optimized grid search over the grid space [27], achieving a reduced computational complexity than the 2-D search in (12). Assume the estimated DOA at the τ -th search step is Φτ = (ϑ τ s , ϕ τ s ), the estimate at the next step is computed using a gradient descent,…”