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An Auditory Illusion of Proximity of the Source Induced by Sonic Crystals.

Spiousas I, Etchemendy PE, Vergara RO, Calcagno ER, Eguia MC - PLoS ONE (2015)

Bottom Line: This effect seems, at first, paradoxical to naïve listeners since the sonic crystal is an obstacle formed by almost densely packed cylindrical scatterers.The results of the acoustical measurements showed that, for a certain frequency range and region in space where the focusing phenomenon takes place, the sonic crystal induces substantial increases in binaural intensity, direct-to-reverberant energy ratio and interaural cross-correlation values, all cues involved in the auditory perception of distance.Consistently, the results of the psychophysical experiment revealed that the presence of the sonic crystal between the sound source and the listener produces a significant reduction of the perceived relative distance to the sound source.

View Article: PubMed Central - PubMed

Affiliation: Laboratorio de Acústica y Percepción Sonora, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina.

ABSTRACT
In this work we report an illusion of proximity of a sound source created by a sonic crystal placed between the source and a listener. This effect seems, at first, paradoxical to naïve listeners since the sonic crystal is an obstacle formed by almost densely packed cylindrical scatterers. Even when the singular acoustical properties of these periodic composite materials have been studied extensively (including band gaps, deaf bands, negative refraction, and birrefringence), the possible perceptual effects remain unexplored. The illusion reported here is studied through acoustical measurements and a psychophysical experiment. The results of the acoustical measurements showed that, for a certain frequency range and region in space where the focusing phenomenon takes place, the sonic crystal induces substantial increases in binaural intensity, direct-to-reverberant energy ratio and interaural cross-correlation values, all cues involved in the auditory perception of distance. Consistently, the results of the psychophysical experiment revealed that the presence of the sonic crystal between the sound source and the listener produces a significant reduction of the perceived relative distance to the sound source.

No MeSH data available.


Related in: MedlinePlus

Positive shifts for each stimuli set (1–5) as a function of frequency and position.Proportion of positive shifts classified into three cases according to their confidence limits (α = 0.05) as a function of frequency, position and stimuli set for group A (top) and group B (bottom). The white region corresponds to statistically significant negative shifts; the gray region corresponds to ambiguous cases where no shift occurred; and the red region corresponds to statistically significant positive shifts, meaning that the source is consistently perceived farther for the without-SC condition.
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pone.0133271.g003: Positive shifts for each stimuli set (1–5) as a function of frequency and position.Proportion of positive shifts classified into three cases according to their confidence limits (α = 0.05) as a function of frequency, position and stimuli set for group A (top) and group B (bottom). The white region corresponds to statistically significant negative shifts; the gray region corresponds to ambiguous cases where no shift occurred; and the red region corresponds to statistically significant positive shifts, meaning that the source is consistently perceived farther for the without-SC condition.

Mentions: In Fig 3 we show the result of this analysis as a function of frequency, position and stimuli set, for group A (top) and B (bottom). This classification leads to a pattern consisting in a majority of positive shifts occurring in the same regions where the acoustical cues are higher (focusing region), for stimuli sets 1–4 in group A and 1–2 for group B. For stimuli sets 1–2 in both groups we can also see a systematic negative shifts for the regions not belonging to the focusing region. Stimuli set 5 on group A and 3–5 on group B give rise to mostly ambiguous cases.


An Auditory Illusion of Proximity of the Source Induced by Sonic Crystals.

Spiousas I, Etchemendy PE, Vergara RO, Calcagno ER, Eguia MC - PLoS ONE (2015)

Positive shifts for each stimuli set (1–5) as a function of frequency and position.Proportion of positive shifts classified into three cases according to their confidence limits (α = 0.05) as a function of frequency, position and stimuli set for group A (top) and group B (bottom). The white region corresponds to statistically significant negative shifts; the gray region corresponds to ambiguous cases where no shift occurred; and the red region corresponds to statistically significant positive shifts, meaning that the source is consistently perceived farther for the without-SC condition.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519286&req=5

pone.0133271.g003: Positive shifts for each stimuli set (1–5) as a function of frequency and position.Proportion of positive shifts classified into three cases according to their confidence limits (α = 0.05) as a function of frequency, position and stimuli set for group A (top) and group B (bottom). The white region corresponds to statistically significant negative shifts; the gray region corresponds to ambiguous cases where no shift occurred; and the red region corresponds to statistically significant positive shifts, meaning that the source is consistently perceived farther for the without-SC condition.
Mentions: In Fig 3 we show the result of this analysis as a function of frequency, position and stimuli set, for group A (top) and B (bottom). This classification leads to a pattern consisting in a majority of positive shifts occurring in the same regions where the acoustical cues are higher (focusing region), for stimuli sets 1–4 in group A and 1–2 for group B. For stimuli sets 1–2 in both groups we can also see a systematic negative shifts for the regions not belonging to the focusing region. Stimuli set 5 on group A and 3–5 on group B give rise to mostly ambiguous cases.

Bottom Line: This effect seems, at first, paradoxical to naïve listeners since the sonic crystal is an obstacle formed by almost densely packed cylindrical scatterers.The results of the acoustical measurements showed that, for a certain frequency range and region in space where the focusing phenomenon takes place, the sonic crystal induces substantial increases in binaural intensity, direct-to-reverberant energy ratio and interaural cross-correlation values, all cues involved in the auditory perception of distance.Consistently, the results of the psychophysical experiment revealed that the presence of the sonic crystal between the sound source and the listener produces a significant reduction of the perceived relative distance to the sound source.

View Article: PubMed Central - PubMed

Affiliation: Laboratorio de Acústica y Percepción Sonora, Universidad Nacional de Quilmes, Bernal, Buenos Aires, Argentina.

ABSTRACT
In this work we report an illusion of proximity of a sound source created by a sonic crystal placed between the source and a listener. This effect seems, at first, paradoxical to naïve listeners since the sonic crystal is an obstacle formed by almost densely packed cylindrical scatterers. Even when the singular acoustical properties of these periodic composite materials have been studied extensively (including band gaps, deaf bands, negative refraction, and birrefringence), the possible perceptual effects remain unexplored. The illusion reported here is studied through acoustical measurements and a psychophysical experiment. The results of the acoustical measurements showed that, for a certain frequency range and region in space where the focusing phenomenon takes place, the sonic crystal induces substantial increases in binaural intensity, direct-to-reverberant energy ratio and interaural cross-correlation values, all cues involved in the auditory perception of distance. Consistently, the results of the psychophysical experiment revealed that the presence of the sonic crystal between the sound source and the listener produces a significant reduction of the perceived relative distance to the sound source.

No MeSH data available.


Related in: MedlinePlus