Olson E S
Physics Department, Princeton University, New Jersey 08544, USA.
J Acoust Soc Am. 1998 Jun;103(6):3445-63. doi: 10.1121/1.423083.
Intracochlear pressure was measured in vivo in the base of the gerbil cochlea. The measurements were made over a wide range of frequencies simultaneously in scalae vestibuli and tympani. Pressure was measured just adjacent to the stapes in scala vestibuli and at a number of positions spaced by tens of micrometers, including a position within several micrometers of the basilar membrane, in scala tympani. Two findings emerged from the basic results. First, the spatial variation in scala tympani pressure indicated that the pressure is composed of two modes, which can be identified with fast and slow waves. Second, at frequencies between 2 and 46 kHz (the upper frequency limit of the measurements) the scala vestibuli pressure adjacent to the stapes had a gain of approximately 30 dB with respect to the pressure in the ear canal, and a phase which decreased linearly with frequency. Thus, over these frequencies the middle ear and its termination in the cochlea operate as a frequency independent transmission line. A subset of the data was analyzed further to derive the velocity of the basilar membrane, the pressure difference across the organ of Corti complex (defined to include the tectorial and basilar membranes) and the specific acoustic impedance of the organ of Corti complex. The impedance was found to be tuned in frequency.
在活体沙鼠耳蜗底部测量了蜗内压力。在蜗前庭和鼓阶中同时在很宽的频率范围内进行了测量。在蜗前庭中靠近镫骨处以及在鼓阶中与基底膜相距几十微米的多个位置测量了压力，包括在距基底膜几微米内的一个位置。从这些基本结果中得出了两个发现。第一，鼓阶压力的空间变化表明该压力由两种模式组成，可分别识别为快波和慢波。第二，在2至46千赫（测量的上限频率）之间的频率下，靠近镫骨处的蜗前庭压力相对于耳道压力有大约30分贝的增益，并且相位随频率线性下降。因此，在这些频率范围内，中耳及其在耳蜗中的终端起到了与频率无关的传输线的作用。对一部分数据进行了进一步分析，以得出基底膜的速度、柯蒂氏器复合体（定义为包括盖膜和基底膜）上的压力差以及柯蒂氏器复合体的特定声阻抗。发现该阻抗在频率上是调谐的。
