This work demonstrates novel flexible sensors for acoustic applications. The sensors have been fabricated using zinc oxide (ZnO) and multi-walled carbon nanotubes (MWCNTs) composite. These nanocomposites exhibit excellent piezoelectric properties, making them highly responsive to vibrations and acoustic signals. As a proof of concept, the prototypes were tested with various acoustic signals including white noise, click track, and DMTF tone. The experimental data has been studied for the sensor's stability, sensitivity, and repeatability. The sensor produced voltage responses of approximately 2.5 V for white noise and 3.0 V for click track signals, respectively. This facile and low-cost fabrication process can yield mass production of these piezoelectric sensors for acoustic applications.