Noise induced hearing loss (NIHL) remains a severe health problem worldwide. Current noise metrics and models have assessment limitations on gradually developing NIHL (GDNIHL). In this study, we apply a complex velocity level (CVL) auditory fatigue model to quantitatively assess the impact of basilar membrane (BM) movement on GDNIHL. The transfer functions of chinchilla and human auditory systems, including the triple-path nonlinear (TRNL) filters to simulate the inner ear responses, are applied to obtain BM velocity distribution. Chinchilla and human experimental hearing loss data are used to validate the proposed CVL model’s effectiveness. The results reveal that the developed CVL model demonstrates high correlations with both chinchilla and human hearing loss data. The linear regression based correlation study indicates the proposed CVL model may accurately predict NIHL in both human and chinchilla.