In this study, we design, fabricate, and thoroughly test a fiber-optic biomimetic microelectromechanical system (MEMS) membrane-type acoustic. A silicon-based coupled-bridge double-diaphragm biomimetic membrane is developed by simulating the auditory organs of parasitic flies. The vibrations of the membrane are detected employing a Fabry-Pérot interferometer composed of optical fibers, thereby enabling the measurement of acoustic signals. The results demonstrate that the fabricated biomimetic membrane exhibits two distinct vibration modes. The packaged sensor demonstrates two resonant frequencies at approximately 810 and 1600 Hz, with minimum detectable sound pressures of 2.76 and 2.17 mPa/Hz^1/2, respectively. In addition, the sensor exhibits a figure-eight directional response pattern. Within an incident angle range of 0°?60°, the amplitude of the sensor varies linearly with the angle. Thus, the results indicate that the proposed sensor holds potential for use in miniaturized soundsource target localization systems.