Periphony-Lattice Mixed-Order Ambisonic Scheme for Spherical Microphone Arrays

Jiho Chang*, Marton Marschall

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

Most methods for sound field reconstruction and spherical beamforming with spherical microphone arrays are mathematically based on the spherical harmonics expansion. In many cases, this expansion is truncated at a certain order as in higher order ambisonics (HOA). This truncation leads to performance that is independent of the incident direction of the sound waves. On the other hand, mixed-order ambisonic (MOA) schemes that select an appropriate subset of spherical harmonics can improve the performance for horizontal directions at the expense of other directions. This paper proposes an MOA scheme called Periphony-Lattice to improve sound field reconstruction performance for horizontally incident sound waves. The proposed scheme is compared with the previously introduced MOA and HOA schemes in terms of theoretical truncation error and performance in sound field reconstruction and spherical beamforming. Computer simulations and measurements are conducted with a spherical array of 52 microphones with a nonuniform layout. The results show that the proposed MOA scheme has better performance in sound field reconstruction and spherical beamforming for horizontal sound waves than the other schemes for a given number of microphones. This scheme can be applied to other spherical array layouts if the number of microphones is greater than that of the required spherical harmonics coefficients, and may improve the horizontal performance.
Original languageEnglish
JournalIEEE/ACM Transactions on Audio, Speech, and Language Processing
Volume26
Pages (from-to)924-936
ISSN2329-9290
DOIs
Publication statusPublished - 2018

Cite this

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title = "Periphony-Lattice Mixed-Order Ambisonic Scheme for Spherical Microphone Arrays",
abstract = "Most methods for sound field reconstruction and spherical beamforming with spherical microphone arrays are mathematically based on the spherical harmonics expansion. In many cases, this expansion is truncated at a certain order as in higher order ambisonics (HOA). This truncation leads to performance that is independent of the incident direction of the sound waves. On the other hand, mixed-order ambisonic (MOA) schemes that select an appropriate subset of spherical harmonics can improve the performance for horizontal directions at the expense of other directions. This paper proposes an MOA scheme called Periphony-Lattice to improve sound field reconstruction performance for horizontally incident sound waves. The proposed scheme is compared with the previously introduced MOA and HOA schemes in terms of theoretical truncation error and performance in sound field reconstruction and spherical beamforming. Computer simulations and measurements are conducted with a spherical array of 52 microphones with a nonuniform layout. The results show that the proposed MOA scheme has better performance in sound field reconstruction and spherical beamforming for horizontal sound waves than the other schemes for a given number of microphones. This scheme can be applied to other spherical array layouts if the number of microphones is greater than that of the required spherical harmonics coefficients, and may improve the horizontal performance.",
author = "Jiho Chang and Marton Marschall",
year = "2018",
doi = "10.1109/TASLP.2018.2800290",
language = "English",
volume = "26",
pages = "924--936",
journal = "IEEE/ACM Transactions on Audio, Speech, and Language Processing",
issn = "2329-9290",
publisher = "IEEE Signal Processing Society",

}

Periphony-Lattice Mixed-Order Ambisonic Scheme for Spherical Microphone Arrays. / Chang, Jiho; Marschall, Marton.

In: IEEE/ACM Transactions on Audio, Speech, and Language Processing, Vol. 26, 2018, p. 924-936.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Periphony-Lattice Mixed-Order Ambisonic Scheme for Spherical Microphone Arrays

AU - Chang, Jiho

AU - Marschall, Marton

PY - 2018

Y1 - 2018

N2 - Most methods for sound field reconstruction and spherical beamforming with spherical microphone arrays are mathematically based on the spherical harmonics expansion. In many cases, this expansion is truncated at a certain order as in higher order ambisonics (HOA). This truncation leads to performance that is independent of the incident direction of the sound waves. On the other hand, mixed-order ambisonic (MOA) schemes that select an appropriate subset of spherical harmonics can improve the performance for horizontal directions at the expense of other directions. This paper proposes an MOA scheme called Periphony-Lattice to improve sound field reconstruction performance for horizontally incident sound waves. The proposed scheme is compared with the previously introduced MOA and HOA schemes in terms of theoretical truncation error and performance in sound field reconstruction and spherical beamforming. Computer simulations and measurements are conducted with a spherical array of 52 microphones with a nonuniform layout. The results show that the proposed MOA scheme has better performance in sound field reconstruction and spherical beamforming for horizontal sound waves than the other schemes for a given number of microphones. This scheme can be applied to other spherical array layouts if the number of microphones is greater than that of the required spherical harmonics coefficients, and may improve the horizontal performance.

AB - Most methods for sound field reconstruction and spherical beamforming with spherical microphone arrays are mathematically based on the spherical harmonics expansion. In many cases, this expansion is truncated at a certain order as in higher order ambisonics (HOA). This truncation leads to performance that is independent of the incident direction of the sound waves. On the other hand, mixed-order ambisonic (MOA) schemes that select an appropriate subset of spherical harmonics can improve the performance for horizontal directions at the expense of other directions. This paper proposes an MOA scheme called Periphony-Lattice to improve sound field reconstruction performance for horizontally incident sound waves. The proposed scheme is compared with the previously introduced MOA and HOA schemes in terms of theoretical truncation error and performance in sound field reconstruction and spherical beamforming. Computer simulations and measurements are conducted with a spherical array of 52 microphones with a nonuniform layout. The results show that the proposed MOA scheme has better performance in sound field reconstruction and spherical beamforming for horizontal sound waves than the other schemes for a given number of microphones. This scheme can be applied to other spherical array layouts if the number of microphones is greater than that of the required spherical harmonics coefficients, and may improve the horizontal performance.

U2 - 10.1109/TASLP.2018.2800290

DO - 10.1109/TASLP.2018.2800290

M3 - Journal article

VL - 26

SP - 924

EP - 936

JO - IEEE/ACM Transactions on Audio, Speech, and Language Processing

JF - IEEE/ACM Transactions on Audio, Speech, and Language Processing

SN - 2329-9290

ER -