  About half of the hot subdwarfs are found to have spectra of composite types,
indicating a main sequence companion of spectral type F-K, and the pulsators
are no exception to this rule. The spectroscopic contamination from the main
sequence stars makes it hard to reliably establish physical parameters for the
hot component, and also makes pulsations harder to detect as the amplitudes are
depressed. The binary fraction of the observed sample of hot subdwarf pulsators
is discussed, as are the biases that are affecting it. Spectroscopic evidence
is presented that clearly demonstrates that the well known sdB pulsator,
EOCeti, is misclassified, and is actually an sdOV star.

Solar and Stellar Astrophysics