Simulated room impulse responses have been proven to be both useful and indispensable for comprehensive testing of acoustic signal processing algorithms while controlling parameters such as the reverberation time, room dimensions, and source-array distance. In this work, a method is proposed for simulating the room impulse responses between a sound source and the microphones positioned on a sph...

This paper describes a method that minimizes the mean squared error (MSE) in estimating the spherical harmonic components of the surface air temperature field. The ratio of the MSE to the variance of the spherical harmonic component is expressed in terms of the length scale Xo, and the positions and weights of the measurement stations. The weights are optimized by the condition of minimizing th...

Spherical microphone arrays provide a new and promising tool for the spatial analysis of complex sound fields. Considerable previous work has investigated the use of spherical microphone arrays for phase-mode beamforming, which relies on the Bessel-weighted spherical harmonic transform of the sound field. In this paper, we investigate the advantages that spherical microphone arrays provide for ...

Spherical harmonic transform plays an important role in research in shape description. Current computation methods involve expensive voxelization, and are prone to numerical errors associated with the size of the voxels. This paper describes a fast and accurate technique for computing spherical harmonic coe cients directly from the description of the mesh.

We describe an algorithm for computing an inverse spherical harmonic transform suitable for graphic processing units (GPU). We use CUDA and base our implementation on a Fortran90 routine included in a publicly available parallel package, shat. We focus our attention on the two major sequential steps involved in the transforms computation, retaining the efficient parallel framework of the origin...

The subspace-based estimation of direction of arrivals (DOAs) of multiple sound sources requires multiple observation data from a microphone array, such that basis of signal subspace can be fully identified. For coherent sources, however, multiple measurements only produce linearly dependent observations, which makes it difficult to separate signal subspace from noise subspace. In order to obta...

[2] If we knew g ∈ SL2(C) had an expression g = kark, then gg∗ = ka2rk, where g∗ is conjugate transpose. This suggests how to determine components k, ar, k ′: by the spectral theorem for positive-definite hermitian operators gg∗, we can find k ∈ SU(2) and a diagonal matrix a2r of positive real eigenvalues, so that gg∗ = ka2rk. We claim that k′ = (kar) −1g ∈ SU(2). Indeed, ( (kar) −1g )( (kar) −...

We present a novel weighted spherical harmonic (SPHARM) representation of cortical surfaces and its application to a cortical thickness analysis in autism. The weighted-SPHARM is a hierarchical smoothing technique given as the solution to a parabolic partial differential equation. The weighted-SPHARM generalizes the classical-SPHARM with an additional parameter that modulates the high frequency...