As Japanese companies now commonly manufacture a wide variety of products in small lots, they frequently change the layouts of their factories. The paths of the automated guided vehicles (AGVs) that cruise the factory floors have to be changed accordingly, but it is difficult to change these paths flexibly when existing magnetic or optical vehicle guiding systems are used. However, moving AGVs play music for safety purposes. This study proposes a system that uses the music as a sound source for detecting vehicle position and guides the AGV using an external controller. In an attempt to develop technology for detecting the position of a sound source in a noisy factory environment, we used the parameter design techniques of quality engineering to optimize the characteristics of the emitted sound as well as methods of recording and processing the sound signals.