PURPOSE: To simply detect the bursting position of an arranged pipe without attaching a sound taking means to the arranged pipe or a valve, by a method wherein asymptotic lines are drawn by using time difference reaching a sound taking means from a bursting position which is, in turn, determined as the cross point of the asymptotic lines.

CONSTITUTION: Spouting sound due to water spouting from a bursting position P is taken by each microphones M1WM3 and sound break is recorded by chart paper to read time difference by the rising part of a break wave form. A sound P is imparted on hyperbolas having fucus points M1, M2 by the time difference of a sound wave reaching microphones M1, M2 from the sound source P. The sound source P is imparted on hyperbolas having focus points M2, M3 from the distance (l) between microphones M2, M3 and the reaching time difference of the sound wave and the cross point of these hyperbolas is the sound source P. When the distance of the sound source and the microphones are spaced apart over a predetermined distance or more, because the hyperbolas approach asymptotic lines, the cross point of the asymtotic lines is approximately determined as the sound source.