Cellular Cooperativity

The ear is sound detector that is remarkably sensitive and selective. As a nonlinear and active system, ears also emit sound, known as otoacoustic emission (OAEs). We investigated the theoretical origins of spontaneous emissions (SOAEs), which appear as idiosyncratic peaks unique to a given ear. Using an established model of locally coupled limit cycle oscillators, we adapted and extended the framework for describing an Anolis lizard ear and explored several specific hypotheses.

We observed that depending on the set of parameters and number of oscillators, the system could become sensitive to initial conditions and stay either stable or unstable. We also conclude that embedding only morphological differences (via frequency or hair cell bundle height) is not enough to generate "unique ears". Finally, we achieved a peak broadening by presenting additive noise to the system both as external and local thermal noise.