Internal stochastic resonance (ISR) in a model of intercellular calcium ion oscillations is investigated under the modulation of two parameters, viz., degree of extracellular stimulation (beta) and leak rate (k(f)). ISR can occur when either beta or k(f) is subjected to a noise. internal stochastic biresonance (ISBR) can occur when noise is added to the two parameters simultaneously. The distance to the bifurcation point is found to be able to enhance or suppress the ISBR, and to affect the number of peaks of ISR. (C) 2004 American Institute of Physics.