  Signatures of coupling between an inertial mode in the convective core and a
gravito-inertial mode in the envelope have been found in four-year Kepler light
curves of 16 rapidly rotating $\gamma\,$Doradus ($\gamma\,$Dor) stars. This
makes it possible to obtain a measurement of the rotation frequency in their
convective core. Despite their similar internal structure and available data,
inertial modes have not yet been reported for slowly pulsating B (SPB) stars.
We aim to provide a numerical counterpart of the recently published theoretical
expressions for the mode-coupling coefficients, $\varepsilon$ and
$\tilde{\varepsilon}$. These coefficients represent the two cases of a
continuous and a discontinuous Brunt-V\"ais\"al\"a frequency profile at the
core-envelope interface, respectively. We used asteroseismic forward models of
two samples consisting of 26 SPB stars and 37 $\gamma\,$Dor stars to infer
their numerical values of $\varepsilon$. The asteroseismically inferred values
of $\varepsilon$ for the two samples are between 0.0 and 0.34. While
$\varepsilon$ is most strongly correlated with the near-core rotation frequency
for $\gamma\,$Dor stars, the fractional radius of the convective core instead
provides the tightest correlation for SPB stars. We find $\varepsilon$ to
decrease mildly as the stars evolve. Our asteroseismic results for the mode
coupling support the theoretical interpretation and reveal that young,
fast-rotating $\gamma\,$Dor stars are most suitable for undergoing couplings
between inertial modes in the rotating convective core and gravito-inertial
modes in the radiative envelope. The phenomenon has been found in 2.4\% of such
pulsators with detected period spacing patterns, whereas it has not been seen
in any of the SPB stars so far. (shortened abstract to meet the arXiv limits)
