02317nas a2200217 4500008004100000022001300041245011300054210006900167260001600236300001400252490000800266520167100274100001401945700001601959700001701975700001701992700001902009700001402028700001602042856004102058 2019 eng d a0003347200aPerformance of Doppler shift compensation in bats varies with species rather than with environmental clutter0 aPerformance of Doppler shift compensation in bats varies with sp cJan-12-2019 a109 - 1200 v1583 a

The performance of vocal motor control is crucial for vocal communication; however, its evolution and ecological drivers are largely unknown. Doppler shift compensation (DSC), which has been found only in bats, represents an excellent model for studying the mechanisms and evolution of vocal control. We tested whether species that are more dependent on DSC for pulse–echo separation have a more precise DSC and whether changes in environmental clutter would result in adjustments in DSC performance. We recorded the echolocation and flight behaviour of the greater horseshoe bat, Rhinolophus ferrumequinum, and the great leaf-nosed bat, Hipposideros armiger, flying through a corridor and a window in turn. The DSC precision in H. armiger was significantly lower than that of R. ferrumequinum; the offset between the reference frequency and resting frequency, however, was not significantly different between the two species. We also studied the DSC of H. armiger flying through windows of different sizes. Their flight speed decreased significantly with reduced window size. However, DSC precision and the offset did not vary significantly with window size. Our results suggest that DSC is more precise in rhinolophids, which have a higher demand for pulse–echo separation by DSC, than in hipposiderids. Changes in environmental clutter do not necessarily result in adjustments of DSC performance. Functional importance associated with high-performance vocal control may be critical in shaping the precision of vocal control in the course of evolution. Instead, habitat clutter encountered by vocalizing animals may not play an important role.

1 aZhang, Yu1 aLin, Aiqing1 aDing, Jianan1 aYang, Xinyao1 aJiang, Tinglei1 aLiu, Ying1 aFeng, Jiang uhttps://bio.acousti.ca/de/node/5788402041nas a2200169 4500008004100000022001400041245014400055210006900199260001600268300001600284490000800300520146900308100001401777700001401791700001501805856005101820 2019 eng d a0001-496600aA biosonar model of finless porpoise ( Neophocaena phocaenoides ) for material composition discrimination of cylinders0 abiosonar model of finless porpoise iNeophocaena phocaenoidesi fo cJan-08-2019 a1362 - 13700 v1463 a

Research into the physical mechanism of odontocetes biosonar has made great progress in the past several decades, especially on wave propagation and biosonar beam formation in the foreheads of odontocetes. Although a number of experimental studies have been performed, the physical mechanism of odontocetes underwater target discrimination has not yet been fully understood. Previous research has experimentally studied the finless porpoise's target discrimination using cylinders different in material [Nakahara, Takemura, Koido, and Hiruda (1997). Mar. Mamm. Sci. 13(4), 639–649]. The authors proposed a computed tomography based finite element biosonar model to simulate the detailed process of a finless porpoise click emission and target detection in order to gain a further understanding of the underlying physical mechanism. The numerical solutions of resonance features of both steel and acrylic cylinders in this study are very consistent with the analytic solutions. Furthermore, the simulated outgoing clicks and echoes match the experiment results measured by Nakahara et al. The beam patterns of the scattered field were extracted and the resonance features of cylinders in different materials were analyzed. This method in this study could be used to study some other odontocetes that are inaccessible for experimental work and could also provide physical information for intelligent biomimetic underwater signal processors design.

1 aFeng, Wen1 aZhang, Yu1 aWei, Chong uhttp://asa.scitation.org/doi/10.1121/1.512298101918nas a2200181 4500008004100000245017100041210006900212260001600281300001100297490000700308520123500315100002101550700001401571700001801585700001901603700001601622856009801638 2019 eng d00aInvestigation on acoustic reception pathways in finless porpoise ( Neophocaena asiaorientalis sunameri ) with insight into an alternative pathway0 aInvestigation on acoustic reception pathways in finless porpoise cJan-01-2019 a0160040 v143 a

Sound transmission and reception are both vital components to odontocete echolocation and daily life. Here, we combine computed tomography (CT) scanning and finite element modeling to investigate the acoustic propagation of finless porpoise (Neophocaena asiaorientalis sunameri) echolocation pulses. The CT scanning and finite element method wave propagation model results support the well-accepted jaw-hearing pathway hypothesis and suggest an additional alternative auditory pathway composed of structures, mandible (lower jaw) and internal mandibular fat, with different acoustic impedances, which may also conduct sounds to the ear complexes. The internal mandibular fat is attached to the ear complex and encased by the mandibles laterally and anteriorly. The simulations show signals in this pathway initially propagate along the solid mandibles and are transmitted to the acoustically coupled soft tissue of the internal mandibular fat which conducts the stimuli posteriorly as it eventually arrives at ear complexes. While supporting traditional theories, this new bone-tissue conduction pathway might be meaningful to understand the hearing and sound reception processes in a wide variety of odontocetes species.

1 aSong, Zhongchang1 aZhang, Yu1 aWang, Xianyan1 aSmith, Adam, B1 aXu, Xiaohui uhttp://stacks.iop.org/1748-3190/14/i=1/a=016004?key=crossref.cd9487fd925bb5ecdc5f0eb7a9bbb813