  The impact of bound states in Landauer-Buttiker scattering approach to
non-equilibrium quantum transport is investigated. We show that the noise power
at frequency $\nu$ is sensitive to all bound states with energies $\omega_b$
satisfying $|\omega_b| < \nu$. We derive the exact expression of the bound
state contribution and compare it to the one produced by the scattering states
alone. It turns out that the bound states lead to specific modifications of
both space and frequency dependence of the total noise power. The theoretical
and experimental consequences of this result are discussed.
