Electrical and Computer Engineering Department, Suffolk University, Boston, Massachusetts, USA.
PLoS One. 2013;8(1):e54876. doi: 10.1371/journal.pone.0054876. Epub 2013 Jan 22.
The motion of isolated seal vibrissae due to low frequency sound in air has been measured using a microscope with a video camera and modeled using an FEM method with good agreement between the measurements and the model; the model has also been used to predict the motion of seal vibrissae in water. The shape of the seal vibrissae is that of a tapered right rectangular prism, unlike that of the previously studied rat vibrissae which are conical in shape. Moreover, unlike rat vibrissae which oscillate in the direction of the sound stimulus, two different modes of vibration of seal vibrissae were observed - one corresponding to the wider side being stimulated and one with the narrow side stimulated. The tuning of the seal vibrissae was much sharper than those of rat vibrissae, with quality factors about three times as large as those of rat vibrissae. As shown by the model, this increased sharpness is caused by the larger cross-sectional areas (by more than a factor of ten) of the seal vibrissae. This increased sharpness may be necessary for seal vibrissae so that they can have tuning in water, where the drag more heavily dampens the tuning than in air. The results suggest that vibrissae tuning may be important in the seal's ability to track the wake of its prey.
已经使用带有摄像头的显微镜测量了空气中低频声音引起的孤立海豹触须的运动，并使用有限元方法 (FEM) 对其进行了建模，测量结果与模型吻合良好；该模型还用于预测海豹触须在水中的运动。与之前研究的呈锥形的老鼠触须不同，海豹触须的形状为逐渐变细的直角矩形棱柱。此外，与老鼠触须在声音刺激方向上的振动不同，观察到海豹触须有两种不同的振动模式——一种对应于较宽的一侧受到刺激，另一种对应于较窄的一侧受到刺激。海豹触须的调谐比老鼠触须尖锐得多，品质因数大约是老鼠触须的三倍。正如模型所示，这种锐度的增加是由海豹触须更大的横截面面积（超过十倍）引起的。这种锐度的增加可能是海豹触须所必需的，以便它们能够在水中进行调谐，在水中，阻力比在空气中更能抑制调谐。研究结果表明，触须调谐可能对海豹追踪其猎物尾流的能力很重要。
