334 research outputs found
Bemerkungen zu dem von dem Herrn B. von Samson vorgeschlagenen Einkommensteuer-Gesetz
http://www.ester.ee/record=b4105276*es
Offene Briefe über die Livländische Grundsteuer-Reform
http://tartu.ester.ee/record=b2408962~S1*es
Die wilde Fasanerie : mit besonderer Berücksichtigung der Baltischen Provinzen
https://www.ester.ee/record=b1414513*es
Improvements of Sound Localization Abilities by the Facial Ruff of the Barn Owl (Tyto alba) as Demonstrated by Virtual Ruff Removal
BACKGROUND:When sound arrives at the eardrum it has already been filtered by the body, head, and outer ear. This process is mathematically described by the head-related transfer functions (HRTFs), which are characteristic for the spatial position of a sound source and for the individual ear. HRTFs in the barn owl (Tyto alba) are also shaped by the facial ruff, a specialization that alters interaural time differences (ITD), interaural intensity differences (ILD), and the frequency spectrum of the incoming sound to improve sound localization. Here we created novel stimuli to simulate the removal of the barn owl's ruff in a virtual acoustic environment, thus creating a situation similar to passive listening in other animals, and used these stimuli in behavioral tests. METHODOLOGY/PRINCIPAL FINDINGS:HRTFs were recorded from an owl before and after removal of the ruff feathers. Normal and ruff-removed conditions were created by filtering broadband noise with the HRTFs. Under normal virtual conditions, no differences in azimuthal head-turning behavior between individualized and non-individualized HRTFs were observed. The owls were able to respond differently to stimuli from the back than to stimuli from the front having the same ITD. By contrast, such a discrimination was not possible after the virtual removal of the ruff. Elevational head-turn angles were (slightly) smaller with non-individualized than with individualized HRTFs. The removal of the ruff resulted in a large decrease in elevational head-turning amplitudes. CONCLUSIONS/SIGNIFICANCE:The facial ruff a) improves azimuthal sound localization by increasing the ITD range and b) improves elevational sound localization in the frontal field by introducing a shift of iso-ILD lines out of the midsagittal plane, which causes ILDs to increase with increasing stimulus elevation. The changes at the behavioral level could be related to the changes in the binaural physical parameters that occurred after the virtual removal of the ruff. These data provide new insights into the function of external hearing structures and open up the possibility to apply the results on autonomous agents, creation of virtual auditory environments for humans, or in hearing aids
Организация и ведение аварийно-спасательных работ при наводнении на акваториях
В данной статье представлена необходимость использования эвакуации населения, исторических и материальных средств при возникновении чрезвычайных ситуаций, как одного из основных способов защиты. Основные особенности организации эвакуации, порядок ее осуществления и принципы руководства.This article presents the need to use the evacuation of the population, historical and material assets in the event of emergencies, as one of the main ways of protection. The main features of the evacuation organization, the procedure for its implementation and the principles of leadership
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