Auditory localization in the northern saw-whet owl, Aegolius acadicus

1989 ◽  
Vol 67 (8) ◽  
pp. 1955-1959 ◽  
Author(s):  
B. J. Frost ◽  
P. J. Baldwin ◽  
M. Csizy
Keyword(s):  
Great Accuracy ◽  
Auditory Localization ◽  
Head Orientation ◽  
Sound Sources ◽  
Slight Tendency ◽  
Search Coil ◽  
Aegolius Acadicus ◽  
Localization Ability ◽  
Search Coil Technique ◽  
Vertical Localization

Although there are several anecdotal reports in the literature that northern saw-whet owls (Aegolius acadicus) have extremely accurate auditory localization abilities, there have been no attempts to quantify these observations. In this study we used the search coil technique to obtain precise measurements of the northern saw-whet owl's head orientation toward either cricket chirps or mouse squeaks presented through speakers at various azimuthal positions. The results indicate owls of this species can orient their heads toward sound sources with great accuracy in the azimuthal plane, yielding mean errors of <1.0°, but show a slight tendency to undershoot more peripherally located sounds. Vertical localization is somewhat less precise, but still very accurate. Subsequent studies will be aimed at elucidating the physiological and anatomical substrates of this extreme accuracy in auditory localization ability.

Synthetic individual binaural audio delivery by pinna image processing

2014 ◽  
Vol 10 (3) ◽  
pp. 239-254 ◽  
Author(s):  
Simone Spagnol ◽  
Michele Geronazzo ◽  
Davide Rocchesso ◽  
Federico Avanzini
Keyword(s):  
Sound Source ◽  
Low Complexity ◽  
Head Orientation ◽  
Sound Sources ◽  
Content Type ◽  
Localization Test ◽  
Subjective Measurements ◽  
Head Related Transfer Function ◽  
Practical Implications ◽  
Better Than

Purpose – The purpose of this paper is to present a system for customized binaural audio delivery based on the extraction of relevant features from a 2-D representation of the listener’s pinna. Design/methodology/approach – The most significant pinna contours are extracted by means of multi-flash imaging, and they provide values for the parameters of a structural head-related transfer function (HRTF) model. The HRTF model spatializes a given sound file according to the listener’s head orientation, tracked by sensor-equipped headphones, with respect to the virtual sound source. Findings – A preliminary localization test shows that the model is able to statically render the elevation of a virtual sound source better than non-individual HRTFs. Research limitations/implications – Results encourage a deeper analysis of the psychoacoustic impact that the individualized HRTF model has on perceived elevation of virtual sound sources. Practical implications – The model has low complexity and is suitable for implementation on mobile devices. The resulting hardware/software package will hopefully allow an easy and low-tech fruition of custom spatial audio to any user. Originality/value – The authors show that custom binaural audio can be successfully deployed without the need of cumbersome subjective measurements.

scholarly journals Eye movements associated with eye closure examined with a scleral search coil technique.

1990 ◽  
Vol 49 (2) ◽  
pp. 185-191 ◽  
Author(s):  
Toru Seo ◽  
Toshio Ikeda ◽  
Takeo Kumoi
Keyword(s):  
Eye Movements ◽  
Search Coil ◽  
Eye Closure ◽  
Search Coil Technique

Oculomotor Reactions in the Cuttlefish, Sepia Officinalis

1970 ◽  
Vol 52 (2) ◽  
pp. 369-384 ◽  
Author(s):  
H. COLLEWIJN
Keyword(s):  
Eye Movements ◽  
Optokinetic Nystagmus ◽  
Eye Position ◽  
Sepia Officinalis ◽  
Search Coil ◽  
Passive Rotation ◽  
Eye Velocity ◽  
Search Coil Technique ◽  
Better Than

1. Eye position in Sepia was measured in restrained animals, using a scleral search coil technique. 2. Optokinetic nystagmus was elicited by drum rotations from 0.035 up to 35°/sec. 3. Passive rotation of Sepia in darkness evoked a transient nystagmus, followed by after-nystagmus at arrest. 4. Combination of these two stimuli yielded the best results, but the ratio eye velocity/surroundings velocity was usually not better than 0.5. 5. Eye movements were conjugate and a closed eye could be driven by a seeing eye. Monocular reactions were smaller than binocular ones, but equal in both directions. 6. Fixation movements could not be demonstrated in the present conditions.

scholarly journals Investigation of an MAA Test With Virtual Sound Synthesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Ruijie Meng ◽  
Jingpeng Xiang ◽  
Jinqiu Sang ◽  
Chengshi Zheng ◽  
Xiaodong Li ◽  
...  
Keyword(s):  
Sound Source ◽  
Test System ◽  
Test Method ◽  
Sound Sources ◽  
Suitable Alternative ◽  
Research Fields ◽  
Significant Difference ◽  
Smallest Detectable Difference ◽  
Localization Ability ◽  
Acoustic Environments

The ability to localize a sound source is very important in our daily life, specifically to analyze auditory scenes in complex acoustic environments. The concept of minimum audible angle (MAA), which is defined as the smallest detectable difference between the incident directions of two sound sources, has been widely used in the research fields of auditory perception to measure localization ability. Measuring MAAs usually involves a reference sound source and either a large number of loudspeakers or a movable sound source in order to reproduce sound sources at a large number of predefined incident directions. However, existing MAA test systems are often cumbersome because they require a large number of loudspeakers or a mechanical rail slide and thus are expensive and inconvenient to use. This study investigates a novel MAA test method using virtual sound source synthesis and avoiding the problems with traditional methods. We compare the perceptual localization acuity of sound sources in two experimental designs: using the virtual presentation and real sound sources. The virtual sound source is reproduced through a pair of loudspeakers weighted by vector-based amplitude panning (VBAP). Results show that the average measured MAA at 0° azimuth is 1.1° and the average measured MAA at 90° azimuth is 3.1° in a virtual acoustic system, meanwhile the average measured MAA at 0° azimuth is about 1.2° and the average measured MAA at 90° azimuth is 3.3° when using the real sound sources. The measurements of the two methods have no significant difference. We conclude that the proposed MAA test system is a suitable alternative to more complicated and expensive setups.

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