The flexible mechanosensors with high sensitivities and fast response speed may advance the wearable and implantable applications as healthcare devices, such as real-time heart rate, pulse and respiration monitoring. Here, we introduce a novel flexible “Electronic Eardrum” (EE) based on single-walled carbon nanotubes, poly-ethylene and poly-dimethylsiloxane with micro-structured pyramid arrays. The EE device shows high sensitivity, high signal-to-noise ratio (~55 dB), and fast response time (76.9 μs) to detect and record sound within 20~13000 Hz frequency domain. The mechanism for sound detecting was investigated and the sensitivity is determined by the micro-structure, thickness and strain state. We also demonstrated that the device is able to distinguish human voices. This unprecedented performance of flexible electronic eardrum has implications for many applications such as implantable acoustical bioelectronics and personal voice recognition.