The Perception of Band-Limited Decorrelation Between Vertically Oriented Loudspeakers

Christopher Gribben, Hyunkook Lee

Research output: Contribution to journalArticle

Abstract

Two experiments have been conducted to investigate the perceptual effect of band-limited interchannel decorrelation between vertically oriented loudspeakers. The perceived vertical image spread (VIS) and tonal quality (TQ) of phantom auditory images have been subjectively assessed in multiple comparison trials. The aim of the study was to find a lower decorrelation boundary that provides a significant increase of VIS, whilst maintaining TQ close to that of the original source. For test stimuli, decorrelation was applied to natural sound sources and noise in groups of octave-bands, where the lowest band was varied between 63 Hz and 8 kHz and the upper band was fixed at 16 kHz, resulting in eight decorrelated conditions for each source. Unprocessed octave-bands below the lower boundary were reproduced simultaneously through the lower main-layer loudspeaker only, and a monophonic main-layer only condition was also included in the comparison alongside the decorrelated stimuli. Results reveal that vertical decorrelation of the 500 Hz octave-band and above tends to significantly increase VIS, similar to that of broadband decorrelation, with little impact on TQ. In some cases, decorrelation of higher octave-bands and above can also produce similar increases of VIS with less impact on TQ, however, this is shown to be largely source-dependent. These results suggest that vertical decorrelation of lower frequencies has little perceptual benefit, and band-limiting vertical decorrelation to higher frequencies is likely to reduce low frequency phase cancellation. Applications of such an approach include 2D-to-3D upmixing and binaural audio rendering, with additional implications for 3D audio recording.
Original languageEnglish
JournalIEEE/ACM Transactions on Audio Speech and Language Processing
Publication statusAccepted/In press - 11 Jan 2020

Fingerprint

Loudspeakers
loudspeakers
Audio recordings
Octave
Vertical
octaves
Acoustic noise
Acoustic waves
stimuli
Low Frequency
Experiments
low frequencies
Multiple Comparisons
Perception
Phantom
Cancellation
cancellation
Rendering
Broadband
Lowest

Cite this

@article{acd102e6628b42129c122eadba552564,
title = "The Perception of Band-Limited Decorrelation Between Vertically Oriented Loudspeakers",
abstract = "Two experiments have been conducted to investigate the perceptual effect of band-limited interchannel decorrelation between vertically oriented loudspeakers. The perceived vertical image spread (VIS) and tonal quality (TQ) of phantom auditory images have been subjectively assessed in multiple comparison trials. The aim of the study was to find a lower decorrelation boundary that provides a significant increase of VIS, whilst maintaining TQ close to that of the original source. For test stimuli, decorrelation was applied to natural sound sources and noise in groups of octave-bands, where the lowest band was varied between 63 Hz and 8 kHz and the upper band was fixed at 16 kHz, resulting in eight decorrelated conditions for each source. Unprocessed octave-bands below the lower boundary were reproduced simultaneously through the lower main-layer loudspeaker only, and a monophonic main-layer only condition was also included in the comparison alongside the decorrelated stimuli. Results reveal that vertical decorrelation of the 500 Hz octave-band and above tends to significantly increase VIS, similar to that of broadband decorrelation, with little impact on TQ. In some cases, decorrelation of higher octave-bands and above can also produce similar increases of VIS with less impact on TQ, however, this is shown to be largely source-dependent. These results suggest that vertical decorrelation of lower frequencies has little perceptual benefit, and band-limiting vertical decorrelation to higher frequencies is likely to reduce low frequency phase cancellation. Applications of such an approach include 2D-to-3D upmixing and binaural audio rendering, with additional implications for 3D audio recording.",
keywords = "3D Audio, Decorrelation, Vertical stereo, Psychoacoustics, Vertical Image Spread",
author = "Christopher Gribben and Hyunkook Lee",
year = "2020",
month = "1",
day = "11",
language = "English",
journal = "IEEE/ACM Transactions on Audio Speech and Language Processing",
issn = "2329-9290",
publisher = "IEEE Advancing Technology for Humanity",

}

TY - JOUR

T1 - The Perception of Band-Limited Decorrelation Between Vertically Oriented Loudspeakers

AU - Gribben, Christopher

AU - Lee, Hyunkook

PY - 2020/1/11

Y1 - 2020/1/11

N2 - Two experiments have been conducted to investigate the perceptual effect of band-limited interchannel decorrelation between vertically oriented loudspeakers. The perceived vertical image spread (VIS) and tonal quality (TQ) of phantom auditory images have been subjectively assessed in multiple comparison trials. The aim of the study was to find a lower decorrelation boundary that provides a significant increase of VIS, whilst maintaining TQ close to that of the original source. For test stimuli, decorrelation was applied to natural sound sources and noise in groups of octave-bands, where the lowest band was varied between 63 Hz and 8 kHz and the upper band was fixed at 16 kHz, resulting in eight decorrelated conditions for each source. Unprocessed octave-bands below the lower boundary were reproduced simultaneously through the lower main-layer loudspeaker only, and a monophonic main-layer only condition was also included in the comparison alongside the decorrelated stimuli. Results reveal that vertical decorrelation of the 500 Hz octave-band and above tends to significantly increase VIS, similar to that of broadband decorrelation, with little impact on TQ. In some cases, decorrelation of higher octave-bands and above can also produce similar increases of VIS with less impact on TQ, however, this is shown to be largely source-dependent. These results suggest that vertical decorrelation of lower frequencies has little perceptual benefit, and band-limiting vertical decorrelation to higher frequencies is likely to reduce low frequency phase cancellation. Applications of such an approach include 2D-to-3D upmixing and binaural audio rendering, with additional implications for 3D audio recording.

AB - Two experiments have been conducted to investigate the perceptual effect of band-limited interchannel decorrelation between vertically oriented loudspeakers. The perceived vertical image spread (VIS) and tonal quality (TQ) of phantom auditory images have been subjectively assessed in multiple comparison trials. The aim of the study was to find a lower decorrelation boundary that provides a significant increase of VIS, whilst maintaining TQ close to that of the original source. For test stimuli, decorrelation was applied to natural sound sources and noise in groups of octave-bands, where the lowest band was varied between 63 Hz and 8 kHz and the upper band was fixed at 16 kHz, resulting in eight decorrelated conditions for each source. Unprocessed octave-bands below the lower boundary were reproduced simultaneously through the lower main-layer loudspeaker only, and a monophonic main-layer only condition was also included in the comparison alongside the decorrelated stimuli. Results reveal that vertical decorrelation of the 500 Hz octave-band and above tends to significantly increase VIS, similar to that of broadband decorrelation, with little impact on TQ. In some cases, decorrelation of higher octave-bands and above can also produce similar increases of VIS with less impact on TQ, however, this is shown to be largely source-dependent. These results suggest that vertical decorrelation of lower frequencies has little perceptual benefit, and band-limiting vertical decorrelation to higher frequencies is likely to reduce low frequency phase cancellation. Applications of such an approach include 2D-to-3D upmixing and binaural audio rendering, with additional implications for 3D audio recording.

KW - 3D Audio

KW - Decorrelation

KW - Vertical stereo

KW - Psychoacoustics

KW - Vertical Image Spread

M3 - Article

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

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

SN - 2329-9290

ER -