  We present a dynamical model describing a predictable human behavior like the
tuning process between singers. The purpose, inspired in physiological and
behavioral grounds of human beings, is sensitive to all Fourier spectrum of
each sound emitted and it contemplates an asymmetric coupling between
individuals. We have recorded several tuning exercises and we have confronted
the experimental evidence with the results of the model finding a very well
agreement between calculated and experimental sonograms.
