2017 Volume 8 Issue 1 Pages 15-24
As an experimental analogy of synchronized hands clapping (Néda et al., 2000), sound-coupled electronic metronomes are introduced. Clicking sounds generated from the driving metronome serve as the sounds of hands clapping, whereas a microphone attached to the driven electronic metronome detects the clicking sounds. In contrast to popular experimental systems of synchronization, e.g., mechanical metronomes put on a same beam, which directly connects oscillators through a material medium, the present system utilizes sound as an indirect coupling medium. In cases of both unidirectional and bidirectional couplings, our experiments showed that the two electronic metronomes are synchronized in such a way that a slow metronome catches up with a fast one. Phase slips, which give rise to intermittent switching between synchronized and desynchronized rhythms, were also observed, resembling the hands clapping in a concert hall. Our mathematical model based on phase oscillators with positive interaction function elucidates the observed results very well. Our system may provide a basic experimental framework for studying synchronization in sound-coupled oscillators including the rhythmic applause.
