He found that the length of time it takes a sound's echo to decay is determined by the absorption of the sound's original energy by surrounding material.
他发现，声音回声衰减的时间长短取决于周围物质对声音原始能量的吸收。
2
Then the different damped oscillation curves and over-damped monotonic decay curves can be obtained for various diameter and length of the pressured tube and various volume of the chamber.
The results indicate that the decay coefficient of the peak value of blast wave with the distance will be reduced as the hole depth (charge length) is increased.