Directional properties of the sound transformation at the ear of four intact echolocating bats, Eptesicus fuscus, were investigated via measurements of the head-related transfer function (HRTF). Contributions of external ear structures to directional features of the transfer functions were examined by remeasuring the HRTF in the absence of the pinna and tragus. The investigation mainly focused on the interactions between the spatial and the spectral features in the bat HRTF.
View Article and Find Full Text PDFThe airflow perturbation device (APD) is a recently redesigned instrument to measure resistance in the respiratory system. The APD is small and easy to use, gives rapid resistance measurements, and can easily separate inhalation from exhalation components. It also possesses some operational characteristics similar to forced oscillation (FO).
View Article and Find Full Text PDF31 college age men and women who consume less than three caffeinated beverages per week agreed to participate as subjects in research on the effects of acute caffeine intake on low intensity task performance. All subjects performed two randomly administered test conditions: (1) caffeine (5 mg/kg) and (2) placebo on separate visits following an initial 1-hr. orientation visit.
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