  In this paper, we study the quasi-normal modes (QNMs) of a scalar field in
the background of a large class of quantum black holes that can be formed from
gravitational collapse of a dust fluid in the framework of effective loop
quantum gravity. The loop quantum black holes (LQBHs) are characterized by
three free parameters, one of which is the mass parameter, while the other two
are purely due to quantum geometric effects. Among these two quantum
parameters, one is completely fixed by black hole thermodynamics and its
effects are negligible for macroscopic black holes, while the second parameter
is completely free (in principle). In the studies of the QNMs of such LQBHs, we
pay particular attention to the difference of the QNMs between LQBHs and
classical ones, so that they can be observed for the current and forthcoming
gravitational wave observations, whereby place the LQBH theory directly under
the test of observations.
