To address weak periodic impacts,strong low-frequency modulation interference,and possible mismatch between the theoretical fault period and the actual impact period in bearing acoustic fault signals,this paper proposes a minimum noise amplitude deconvolution (MNAD) impact enhancement method based on time synchronous averaging (TSA) period refinement.The proposed method first performs band-pass preprocessing on the raw acoustic signal.Candidate periods are then constructed within the neighborhood of the theoretical fault period,and the refined period is determined according to the impulsiveness, period consistency,and fault-harmonic prominence of the TSA template.Subsequently,the refined fault frequency is introduced into MNAD for deconvolution-based enhancement.Finally,the intra-period impact phase is estimated from the TSA template,and soft periodic gating is used to further highlight the periodic impacts.Experimental results show that the proposed method can enhance repetitive impact structures in inner-race and rolling-element fault acoustic signals and improve the distinguishability of characteristic frequencies and their harmonics in the envelope spectrum.