  We undertake a detailed numerical study of the twin phenomena of stochastic
and vibrational resonance in a discrete model system in the presence of
bichromatic input signal. A two parameter cubic map is used as the model that
combines the features of both bistable and threshold settings. Our analysis
brings out several interesting results, such as, the existence of a cross over
behaviour from vibrational to stochastic resonance and the possibility of using
stochastic resonance as a filter for the selective detection/transmission of
the component frequencies in a composite signal. The study also reveals a
fundamental difference between the bistable and threshold mechanisms with
respect to amplification of a multi signal input.
