In this research, a biomimetic acoustic sensor that can mimic the functional properties of basilar membrane in mammalian cochlea was fabricated with PMN-PT piezoelectric cantilever array. The piezoelectric cantilever array with ten different lengths was designed to obtain different resonant frequencies. It was fabricated by semiconductor processes and was poled to generate an electrical signal from an audible sound source. The fabricated acoustic sensor was tested by experimental setup. As an experimental result, the resonant frequencies of each cantilever and corresponding electrical signals were measured from 490Hz to 13,600Hz and the displacement sensitivity was measured with the audible frequency range.