  We theoretically investigate the acoustic analogues of high-angular-momentum
rotating black holes in exciton-polariton condensates. Performing numerical
simulations of a long-lived ring-shaped condensate configuration with an
acoustic horizon and ergoregion for high angular momentum states, we observed a
quasi-stable state near critical angular momentum where the acoustic black hole
horizon disappears. Our findings offer an insight into the quantum nature of
the instability of naked singularity.
