A STOCHASTIC-MODEL OF 1 F PHONON-NUMBER FLUCTUATIONS/

We propose a stochastic model of phonon-number fluctuations that allow s to simulate 1/f-like behavior. The fluctuation process is described as a random walk on the ladder of energy levels of a harmonic oscillat or. Two characteristic time scales are involved in the process: the me an life time of states tau(l) and the correlation time tau(c). When th e ratio tau(c)/tau(l) is large, the 1/f-like spectrum is observed with in the frequency range 1/tau(c)<f<1/tau(l). Conditions for large value s of the ratio are discussed.