  A perturbed black hole emits gravitational radiation, usually termed the
ringdown signal, whose frequency and time-constant depends on the mass and spin
of the black hole. I investigate the case of a binary black hole merger
resulting from two initially non-spinning black holes of various mass ratios,
in quasi-circular orbits. The observed ringdown signal will be determined,
among other things, by the black hole's spin-axis orientation with respect to
Earth, its sky position and polarization angle - parameters which can take any
values in a particular observation. I have carried out a statistical analysis
of the effect of these variables, focusing on detection and measurement of the
multimode ringdown signals using the reformulated European LISA mission, Next
Gravitational-Wave Observatory, NGO, the third generation ground-based
observatory, Einstein Telescope and the advanced era detector, aLIGO. To the
extent possible I have discussed the effect of these results on plausible event
rates, as well as astrophysical implications concerning the formation and
growth of supermassive and intermediate mass black holes.
