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Binaural sound localizer for azimuthal movement detection based on diffraction.

Kim K, Choi A - Sensors (Basel) (2012)

Bottom Line: The gradient analysis of the ILD between the structured and unstructured microphone demonstrates the rotation directions as clockwise, counter clockwise, and no rotation of the sound source.Acoustic experiments with different types of sound source over a wide range of target movements show that the average true positive and false positive rates are 67% and 16%, respectively.Spectral analysis demonstrates that the low frequency delivers decreased true and false positive rates and the high frequency presents increases of both rates, overall.

View Article: PubMed Central - PubMed

Affiliation: Division of Electronics & Electrical Engineering, Dongguk University-Seoul, Seoul 100-715, Korea. kwkim@dongguk.edu

ABSTRACT
Sound localization can be realized by utilizing the physics of acoustics in various methods. This paper investigates a novel detection architecture for the azimuthal movement of sound source based on the interaural level difference (ILD) between two receivers. One of the microphones in the system is surrounded by barriers of various heights in order to cast the direction dependent diffraction of the incoming signal. The gradient analysis of the ILD between the structured and unstructured microphone demonstrates the rotation directions as clockwise, counter clockwise, and no rotation of the sound source. Acoustic experiments with different types of sound source over a wide range of target movements show that the average true positive and false positive rates are 67% and 16%, respectively. Spectral analysis demonstrates that the low frequency delivers decreased true and false positive rates and the high frequency presents increases of both rates, overall.

No MeSH data available.


(a) Position of source and receiver for conventional noise barrier. (b) Position of source and receiver for RDD system.
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f2-sensors-12-10584: (a) Position of source and receiver for conventional noise barrier. (b) Position of source and receiver for RDD system.

Mentions: The level of sound is reduced by an extended barrier as, for example, a wall or a building, and that the obstacle casts an acoustic signal shadow. Nevertheless, the shadow is not ideal because sound is diffracted around the edges of the obstacle. The level attenuation in decibels caused by a height can be calculated for the straight, constant, and infinite length barrier by using the below equation given by Kurze and Anderson [17]:(1)ΔL=5dB+20log(2πN)12tanh(2πN)12dB and N=2(A+B−d)λwhere (A+B) is the shortest path length over the edge, from the source to the receiver in the barrier shadow zone and d is the direct path distance between source and receiver through the barrier. λ is the wave length of the sound. The parameters are illustrated in Figure 2(a).


Binaural sound localizer for azimuthal movement detection based on diffraction.

Kim K, Choi A - Sensors (Basel) (2012)

(a) Position of source and receiver for conventional noise barrier. (b) Position of source and receiver for RDD system.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472845&req=5

f2-sensors-12-10584: (a) Position of source and receiver for conventional noise barrier. (b) Position of source and receiver for RDD system.
Mentions: The level of sound is reduced by an extended barrier as, for example, a wall or a building, and that the obstacle casts an acoustic signal shadow. Nevertheless, the shadow is not ideal because sound is diffracted around the edges of the obstacle. The level attenuation in decibels caused by a height can be calculated for the straight, constant, and infinite length barrier by using the below equation given by Kurze and Anderson [17]:(1)ΔL=5dB+20log(2πN)12tanh(2πN)12dB and N=2(A+B−d)λwhere (A+B) is the shortest path length over the edge, from the source to the receiver in the barrier shadow zone and d is the direct path distance between source and receiver through the barrier. λ is the wave length of the sound. The parameters are illustrated in Figure 2(a).

Bottom Line: The gradient analysis of the ILD between the structured and unstructured microphone demonstrates the rotation directions as clockwise, counter clockwise, and no rotation of the sound source.Acoustic experiments with different types of sound source over a wide range of target movements show that the average true positive and false positive rates are 67% and 16%, respectively.Spectral analysis demonstrates that the low frequency delivers decreased true and false positive rates and the high frequency presents increases of both rates, overall.

View Article: PubMed Central - PubMed

Affiliation: Division of Electronics & Electrical Engineering, Dongguk University-Seoul, Seoul 100-715, Korea. kwkim@dongguk.edu

ABSTRACT
Sound localization can be realized by utilizing the physics of acoustics in various methods. This paper investigates a novel detection architecture for the azimuthal movement of sound source based on the interaural level difference (ILD) between two receivers. One of the microphones in the system is surrounded by barriers of various heights in order to cast the direction dependent diffraction of the incoming signal. The gradient analysis of the ILD between the structured and unstructured microphone demonstrates the rotation directions as clockwise, counter clockwise, and no rotation of the sound source. Acoustic experiments with different types of sound source over a wide range of target movements show that the average true positive and false positive rates are 67% and 16%, respectively. Spectral analysis demonstrates that the low frequency delivers decreased true and false positive rates and the high frequency presents increases of both rates, overall.

No MeSH data available.