2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/21234The system discussed recently in L. Cao and D. J. Wu, Europhys. Lett. {\bf 61}, (2003) 593 merely reproduces properties of the input signal.Submitted to Europhysics Letters; 2 pages in epl.cls style; minor changes as compared with the previous versionStatistical MechanicsComment on "Stochastic resonance in a linear system with signal-modulated noise"text