Abstract: The decline of intensity-response sensitivity and rising of hearing threshold are direct phenomena with hearing loss. To investigate the hearing loss resulted distortion of auditory information expression in cochlea with intensity sensitivity decline, which influences speech intelligibility, and improve the performance of hearing aids, the intensity-response sensitivity decline resulted distortion of the basilar membrane vibration was studied through animal experiment in this research. It is revealed that with intensity sensitivity decline of cochlear basilar response, the amplitude-sound pressure level relation transfers from nonlinearity to linearity, while the amplitudes of combination tones gradually decrease, until they disappear. The tuning curve becomes blunted, and the characteristic frequency shifts to higher frequency.