Abstract Ensemble empirical mode decomposition (EEMD) is a noiseassisted method and also a significant improvement on empirical mode decomposition (EMD). However, the EEMD method lacks a guide to choosing the appropriate amplitude of added noise and its computation efficiency is fairly low. To alleviate the problems of the EEMD method, the improved complementary EEMD method (ICEEMD) was proposed. Furthermore, the ICEEMD method was used to analyze realistic gearbox faulty signals. The results indicate that the ICEEMD method has some advantages over the EEMD method in alleviating the mode mixing and splitting as well as reducing the time cost and also outperforms the CEEMD method in alleviating the mode mixing and splitting. The paper also indicates that the ICEEMD method seems to be an effective and efficient method for processing gearbox fault signals
