Gammatone ?lterbanks are widely used in computational auditory models for modeling the peripheral ?ltering function of the cochlea. However, the high computational complexity and time consumption limits its usage in portable acoustic applications. To address this issue, a realtime and ef?cient digital implementation of Gammatone ?lterbank is proposed. The decomposed signal can be resynthesized by summation directly. We systematically examine the Gammatone ?lterbank with perceptual evaluation of speech quality (PESQ), ShortTime Objective Intelligibility (STOI) , signal-to-noise ratio (SNR) and computational complexity. Evaluations and comparisons show that the proposed method has good performance and less computational complexity.