We proposed a method for estimating the position of mono channel microphones using the sound from loudspeakers with hidden time synchronization waveforms in the audio signal. Unlike previous studies based on the SS (Spread Spectrum) technique, we used OFDM (Orthogonal Frequency Division Multiplexing) time synchronization signal embedded in the sound, maintaining the inaudibility of the embedded signal. While the microphone detects the time synchronization waveform, users remain unaware of the hidden time synchronization signal. With this hidden signal, we can successfully obtain the location of the microphone while the music is playing. We have anticipated various applications of our proposed method such as a configuration of multichannel audio systems or spotting target locations for private listening zones generated by a speaker array.