Tampere University of Technology

TUTCRIS Research Portal

Local Time-Domain Spherical Harmonic Spatial Encoding for Wave-Based Acoustic Simulation

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Pages (from-to)617-621
Number of pages5
JournalIEEE Signal Processing Letters
Issue number4
Publication statusPublished - 1 Apr 2019
Publication typeA1 Journal article-refereed


Volumetric time-domain simulation methods, such as the finite difference time domain method, allow for a fine-grained representation of the dynamics of the acoustic field. A key feature of such methods is complete access to the computed field, normally represented over a Cartesian grid. Simple solutions to the problem of extracting spatially encoded signals, necessary in virtual acoustics applications, result. In this letter, a simple time-domain representation of spatially encoded spherical harmonic signals is written directly in terms of spatial derivatives of the acoustic field at the receiver location. In a discrete setting, encoded signals may be obtained, at very low computational cost and latency, using local approximations with minimal number of grid points, and avoiding large convolutions and frequency-domain block processing of previous approaches. Numerical results illustrating receiver directivity and computed time-domain responses are presented, as well as numerical solution drift associated with repeated time integration.


  • acoustic field, acoustic signal detection, acoustic signal processing, encoding, finite difference time-domain analysis, frequency-domain analysis, time-domain analysis, repeated time integration, computed time-domain responses, frequency-domain block processing, spatially encoded spherical harmonic signals, simple time-domain representation, virtual acoustics applications, spatially encoded signals, computed field, fine-grained representation, finite difference time domain method, volumetric time-domain simulation methods, wave-based acoustic simulation, local time-domain spherical harmonic spatial encoding, Time-domain analysis, Acoustics, Encoding, Harmonic analysis, Finite difference methods, Three-dimensional displays, Receivers, Finite difference time domain (FDTD), room acoustics, spatial audio, microphone array, spherical harmonics, ambisonics

Publication forum classification

Field of science, Statistics Finland