  Recent photometric observations of massive stars have identified a
low-frequency power excess which appears as stochastic low-frequency
variability in light curve observations. We present the oscillation properties
of high resolution hydrodynamic simulations of a 25 $\mathrm{M}_\odot$ star
performed with the PPMStar code. The model star has a convective core mass of
$\approx\, 12\, \mathrm{M}_\odot$ and approximately half of the envelope
simulated. From this simulation, we extract light curves from several
directions, average them over each hemisphere, and process them as if they were
real photometric observations. We show how core convection excites waves with a
similar frequency as the convective time scale in addition to significant power
across a forest of low and high angular degree $l$ modes. We find that the
coherence of these modes is relatively low as a result of their stochastic
excitation by core convection, with lifetimes on the order of 10s of days.
Thanks to the still significant power at higher $l$ and this relatively low
coherence, we find that integrating over a hemisphere produces a power spectrum
that still contains measurable power up to the Brunt--V\"ais\"al\"a frequency.
These power spectra extracted from the stable envelope are qualitatively
similar to observations, with same order of magnitude yet lower characteristic
frequency. This work further shows the potential of long-duration,
high-resolution hydrodynamic simulations for connecting asteroseismic
observations to the structure and dynamics of core convection and the
convective boundary.
