Firzlaff Uwe, Schuller Gerd
Department Biologie II, Ludwig-Maximilians-Universität, Luisenstr. 14, 80333 München, Germany.
Hear Res. 2003 Nov;185(1-2):110-22. doi: 10.1016/s0378-5955(03)00281-8.
The directional dependence of sound pressure transformation of head and pinna has been measured in the phyllostomid bat Phyllostomus discolor for the frontal hemisphere using a maximum length sequence method. The azimuthal position of the axis of highest pinna gain came closer to the midsagital plane with increasing frequency. The acoustic axis of highest pinna gain was further characterized by an increase of the elevation angle with increasing frequency and a specific decrease at 55 kHz. Additionally, a spectral notch separated two regions of high and low frequency hearing at specific elevation and frequency combinations. The special influence of the tragus on the position of the pinna gain axis and the spectral notches is demonstrated. The functional implications of the spectral notch for hearing in P. discolor are discussed.
使用最大长度序列法，在叶口蝠（Phyllostomus discolor）的额叶半球测量了头部和耳廓声压转换的方向依赖性。随着频率增加，耳廓增益最高轴的方位角位置更接近矢状中线平面。耳廓增益最高的声轴的进一步特征是，随着频率增加仰角增大，在55千赫时出现特定减小。此外，在特定仰角和频率组合下，一个频谱陷波将高低频听力的两个区域分开。证明了耳屏对耳廓增益轴位置和频谱陷波的特殊影响。讨论了频谱陷波对叶口蝠听力的功能意义。
