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Reaching nearby sources: comparison between real and virtual sound and visual targets.

Parseihian G, Jouffrais C, Katz BF - Front Neurosci (2014)

Bottom Line: The current study concerns localization and pointing accuracy by examining source positions in the peripersonal space, specifically those associated with a typical tabletop surface.Results show no effect on the reporting hand with azimuthal errors increasing equally for the most extreme source positions.Various potential reasons for this discrepancy are discussed with several proposals for improving distance perception in peripersonal virtual environments.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire de Mécanique et d'Informatique pour les Sciences de l'Ingénieur, LIMSI - CNRS, Universite Paris Sud Orsay, France.

ABSTRACT
Sound localization studies over the past century have predominantly been concerned with directional accuracy for far-field sources. Few studies have examined the condition of near-field sources and distance perception. The current study concerns localization and pointing accuracy by examining source positions in the peripersonal space, specifically those associated with a typical tabletop surface. Accuracy is studied with respect to the reporting hand (dominant or secondary) for auditory sources. Results show no effect on the reporting hand with azimuthal errors increasing equally for the most extreme source positions. Distance errors show a consistent compression toward the center of the reporting area. A second evaluation is carried out comparing auditory and visual stimuli to examine any bias in reporting protocol or biomechanical difficulties. No common bias error was observed between auditory and visual stimuli indicating that reporting errors were not due to biomechanical limitations in the pointing task. A final evaluation compares real auditory sources and anechoic condition virtual sources created using binaural rendering. Results showed increased azimuthal errors, with virtual source positions being consistently overestimated to more lateral positions, while no significant distance perception was observed, indicating a deficiency in the binaural rendering condition relative to the real stimuli situation. Various potential reasons for this discrepancy are discussed with several proposals for improving distance perception in peripersonal virtual environments.

No MeSH data available.


Related in: MedlinePlus

(A) Mean of all subjects' reported azimuth as a function of stimuli azimuth for each rendering condition: visual (▴), real sound (◾), and virtual sound (•). Error bars show one standard deviation across the subjects. Gray line shows unity. (B) Mean of all subjects' reported distance as a function of stimuli distance for each rendering condition: visual (▴), real sound (◾), and virtual sound (•). Error bars show one standard deviation across the subjects for each condition. Solid gray lines show linear regression curves for each modality. Gray line shows unity.
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Figure 4: (A) Mean of all subjects' reported azimuth as a function of stimuli azimuth for each rendering condition: visual (▴), real sound (◾), and virtual sound (•). Error bars show one standard deviation across the subjects. Gray line shows unity. (B) Mean of all subjects' reported distance as a function of stimuli distance for each rendering condition: visual (▴), real sound (◾), and virtual sound (•). Error bars show one standard deviation across the subjects for each condition. Solid gray lines show linear regression curves for each modality. Gray line shows unity.

Mentions: Figure 4A presents the mean and standard deviation of reported azimuth as a function of stimuli azimuth. The mean and standard deviation of the unsigned azimuth error are presented in Table 3. First, the visual condition shows good estimation of azimuth, with a low variability (mean error of 2.79° ± 4.51°). For frontal locations, the mean unsigned error is 1.61° ± 1.27°. This error increases with azimuth to 2° for ±30° locations and to 4° for ±60° locations, as does the dispersion. It can be noticed that the lateral error corresponds to a slight underestimation of the azimuth. Second, results for real sound condition are similar to the first experiment's results. They highlight good accuracy at 0° with a mean error of 5.7°, and lower accuracy at the sides. Third, virtual sound condition showed lower performance results in terms of azimuth estimation. The mean absolute error at 0° is 10.79° ± 10.03°. The ±30° and ±60° locations are shifted by approximately 15° to the side (except −30° locations which are reported at −60°).


Reaching nearby sources: comparison between real and virtual sound and visual targets.

Parseihian G, Jouffrais C, Katz BF - Front Neurosci (2014)

(A) Mean of all subjects' reported azimuth as a function of stimuli azimuth for each rendering condition: visual (▴), real sound (◾), and virtual sound (•). Error bars show one standard deviation across the subjects. Gray line shows unity. (B) Mean of all subjects' reported distance as a function of stimuli distance for each rendering condition: visual (▴), real sound (◾), and virtual sound (•). Error bars show one standard deviation across the subjects for each condition. Solid gray lines show linear regression curves for each modality. Gray line shows unity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4151089&req=5

Figure 4: (A) Mean of all subjects' reported azimuth as a function of stimuli azimuth for each rendering condition: visual (▴), real sound (◾), and virtual sound (•). Error bars show one standard deviation across the subjects. Gray line shows unity. (B) Mean of all subjects' reported distance as a function of stimuli distance for each rendering condition: visual (▴), real sound (◾), and virtual sound (•). Error bars show one standard deviation across the subjects for each condition. Solid gray lines show linear regression curves for each modality. Gray line shows unity.
Mentions: Figure 4A presents the mean and standard deviation of reported azimuth as a function of stimuli azimuth. The mean and standard deviation of the unsigned azimuth error are presented in Table 3. First, the visual condition shows good estimation of azimuth, with a low variability (mean error of 2.79° ± 4.51°). For frontal locations, the mean unsigned error is 1.61° ± 1.27°. This error increases with azimuth to 2° for ±30° locations and to 4° for ±60° locations, as does the dispersion. It can be noticed that the lateral error corresponds to a slight underestimation of the azimuth. Second, results for real sound condition are similar to the first experiment's results. They highlight good accuracy at 0° with a mean error of 5.7°, and lower accuracy at the sides. Third, virtual sound condition showed lower performance results in terms of azimuth estimation. The mean absolute error at 0° is 10.79° ± 10.03°. The ±30° and ±60° locations are shifted by approximately 15° to the side (except −30° locations which are reported at −60°).

Bottom Line: The current study concerns localization and pointing accuracy by examining source positions in the peripersonal space, specifically those associated with a typical tabletop surface.Results show no effect on the reporting hand with azimuthal errors increasing equally for the most extreme source positions.Various potential reasons for this discrepancy are discussed with several proposals for improving distance perception in peripersonal virtual environments.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire de Mécanique et d'Informatique pour les Sciences de l'Ingénieur, LIMSI - CNRS, Universite Paris Sud Orsay, France.

ABSTRACT
Sound localization studies over the past century have predominantly been concerned with directional accuracy for far-field sources. Few studies have examined the condition of near-field sources and distance perception. The current study concerns localization and pointing accuracy by examining source positions in the peripersonal space, specifically those associated with a typical tabletop surface. Accuracy is studied with respect to the reporting hand (dominant or secondary) for auditory sources. Results show no effect on the reporting hand with azimuthal errors increasing equally for the most extreme source positions. Distance errors show a consistent compression toward the center of the reporting area. A second evaluation is carried out comparing auditory and visual stimuli to examine any bias in reporting protocol or biomechanical difficulties. No common bias error was observed between auditory and visual stimuli indicating that reporting errors were not due to biomechanical limitations in the pointing task. A final evaluation compares real auditory sources and anechoic condition virtual sources created using binaural rendering. Results showed increased azimuthal errors, with virtual source positions being consistently overestimated to more lateral positions, while no significant distance perception was observed, indicating a deficiency in the binaural rendering condition relative to the real stimuli situation. Various potential reasons for this discrepancy are discussed with several proposals for improving distance perception in peripersonal virtual environments.

No MeSH data available.


Related in: MedlinePlus