  A delay is known to induce multistability in periodic systems. Under
influence of noise, coupled oscillators can switch between coexistent orbits
with different frequencies and different oscillation patterns. For coupled
phase oscillators we reduce the delay system to a non-delayed Langevin
equation, which allows us to analytically compute the distribution of
frequencies, and their corresponding residence times. The number of stable
periodic orbits scales with the roundtrip delay time and coupling strength, but
the noisy system visits only a fraction of the orbits, which scales with the
square root of the delay time and is independent of the coupling strength. In
contrast, the residence time in the different orbits is mainly determined by
the coupling strength and the number of oscillators, and only weakly dependent
on the coupling delay. Finally we investigate the effect of a detuning between
the oscillators. We demonstrate the generality of our results with
delay-coupled FitzHugh-Nagumo oscillators.
