In 1986, the writer et al. suggested that a whole geosound sequence can be obviously divided into five periods, namely period of acoustic emission generating, period of acoustic emission accelerated, relativelly quiescent period of acoustic emission, period of main acoustic emission and period of acoustic emission decayed, based on the variation process of geosound wave form before and after earthquakes.
In this paper, the application and significance of the geosound sequence in the short-term and imminent prediction are further studied. In fact, the obtained results indicate that the observations of geosound on-site are compatible with the data of seismicity and experimental results in laboratory at all, so the geosound sequence might probably be used in the short-term and imminent pediction. Especially, the relative quiescent period in acoustic emission before earthquake can be taken as an impending earthquake signal.