Monte Carlo simulations of an atmospheric phase screen, based on a Kolmogorov spectrum of phase fluctuations,
were performed. Speckle patterns produced from the phase screens were used to derive statistical properties of
power spectra and bispectra of speckle interferograms. We present the bispectral modulation transfer function and
its signal-to-noise ratio at high light levels. The results confirm the validity of a heuristic treatment based on an
interferometric picture of speckle pattern formation in deriving the attenuation factor and the signal-to-noise ratio
of the bispectral modulation transfer function in the mid-spatial-frequency range. The derived modulation
transfer function is also interpreted in terms of the signal-to-noise ratio at low light levels. A general expression of
the signal-to-noise ratio of the bispectrum is derived as a function of the transfer functions of the telescope, the
number of speckles, and the mean photon counts in the mid-spatial-frequency range
