By analysing the causes of the machinery impact noise,the authors of this paper mainlydiscuss how to analyse it by the technique of impact stimulation both in theory and practice.

The impact noise excitation is discussed,and the time-history inputting models for impact noise excitations are founded.

Studied also are the noise spectrum characteristics and its relation with air pressure and intermittency during exhaust in addition to ways of eliminating impact noise.

Speech enhancement approach based on signal subspace with multi-input in impulsive noise;

Joint diagonalization DOA matrix method in impulsive noise environments;

Fast DOA estimation in an impulsive noise environment;

Impulse,vibration and noise are ordinary troubles in hydraulic system,which is an available measure to reduce impulse noise while wave attenuator is used in the system.