01898nas a2200157   4500008004100000245007400041210006900115520139500184100001501579700002201594700001501616700002301631700001701654700001801671856005101689       2019                        eng d00aHigh-frequency soundfield microphone for the analysis of bat biosonar0 aHighfrequency soundfield microphone for the analysis of bat bios3 a<p>Numerous bat species emit wideband frequency-modulated signals for echolocation to hunt prey and avoid obstacles. Research investigating the behavioral and physiological responses of bats to echoes typically includes analysis of acoustic signals from microphones and/or microphone arrays, using time difference of arrival between array elements or the microphones to locate flying bats (azimuth and elevation). This has provided insight into transmission adaptations such as pulse duration and duty cycle with respect to target distance, clutter, and interferers. Microphones recording transmitted signals and echoes near a stationary bat provide sound pressure as a function of time but no directional information. In this work, the authors propose a spatial audio/soundfield microphone array to both track bats in flight and pinpoint the directions of echoes received by a bat. The authors introduce an ultrasonic (20&ndash;80&thinsp;kHz) tetrahedral soundfield microphone to capture bat sounds up to 80&thinsp;kHz. A spatial audio decoding technique called high angular resolution planewave expansion (HARPEx) supplies angle and elevation estimates, either for a flying bat based on the bat pulses or for targets based on echoes. Experiments using the soundfield microphone and HARPEx show that the approach accurately estimates the sound direction of arrival in both scenarios.</p>
1 aLee, Hyeon1 aRoan, Michael, J.1 aMing, Chen1 aSimmons, James, A.1 aWang, Ruihao1 aMüller, Rolf  uhttp://asa.scitation.org/doi/10.1121/1.513965201931nas a2200181   4500008004100000022001400041245009000055210006900145260001600214300001600230490000800246520137800254100001701632700001601649700001501665700001801680856005101698       2017                        eng d  a0001-496600aHorseshoe bats and Old World leaf-nosed bats have two discrete types of pinna motions0 aHorseshoe bats and Old World leafnosed bats have two discrete ty  cJan-05-2017  a3011 - 30170 v1413 a<p>Horseshoe bats (Rhinolophidae) and the related Old World leaf-nosed bats (Hipposideridae) both show conspicuous pinna motions as part of their biosonar behaviors. In the current work, the kinematics of these motions in one species from each family (Rhinolophus ferrumequinum and Hipposideros armiger) has been analyzed quantitatively using three-dimensional tracking of landmarks placed on the pinna. The pinna motions that were observed in both species fell into two categories: In &ldquo;rigid rotations&rdquo; motions the geometry of the pinna was preserved and only its orientation in space was altered. In &ldquo;open&ndash;close motions&rdquo; the geometry of the pinna was changed which was evident in a change of the distances between the landmark points. A linear discriminant analysis showed that motions from both categories could be separated without any overlap in the analyzed data set. Hence, bats from both species have two separate types of pinna motions with apparently no transitions between them. The deformations associated with open&ndash;close pinna motions in Hipposideros armiger were found to be substantially larger compared to the wavelength associated with the largest pulse energy than in Rhinolophus ferrumequinum (137% vs 99%). The role of the two different motions in the biosonar behaviors of the animals remains to be determined.</p>
1 aYin, Xiaoyan1 aQiu, Peiwen1 aYang, Lili1 aMüller, Rolf  uhttp://asa.scitation.org/doi/10.1121/1.4982042