  Coupled hair cells of the auditory and vestibular systems perform the crucial
task of converting the energy of sound waves and ground-borne vibrations into
ionic currents. We mechanically couple groups of living, active hair cells with
artificial membranes, thus mimicking in vitro the coupled dynamical system. We
identify chimera states and frequency clustering in the dynamics of these
coupled nonlinear, autonomous oscillators. We find that these dynamical states
can be reproduced by our numerical model with heterogeneity of the parameters.
Further, we find that this model is most sensitive to external signals when
poised at the onset of synchronization, where chimera and cluster states are
likely to form. We therefore propose that the partial synchronization in our
experimental system is a manifestation of a system poised at the verge of
synchronization with optimal sensitivity.
