The masking effect of human hearing is modeled by lateral and unilateral inhibition, and tested for isolated word recognition tasks. Frequency masking suppresses unwanted signals close to the dominant signal of interest in frequency domain, and the weak signals following dominant ones in the time are suppressed by temporal forward masking. The masking effect filters out unimportant signals, which may improve the performance of speech recognition systems. With the parameters derived from the psychological observations, proposed model shows good analogy to psychoacoustic masking effects as well as superior recognition performance. (C) 2003 Elsevier Science B.V. All rights reserved.