In this paper, we present the propagation of acoustic waves in switchable device within a specific frequency range. Our proposed system comprises an input and three output lines (three channels), initially acting as an amplitude divider which splits an incident acoustic wave to the three output channels. We demonstrate theoretically that the introduction of a resonator of length d2 along the waveguide of length dc, connecting the output channels to the input channel of our system, efficiently modulates the acoustic signal, Consequently, the input signal is entirely transmitted at the first output line T1 = 1 while transmissions through the second and third channels, as well as reflection, are nullified T2 = T3 = R = 0. The theoretical analysis is based on the Transfer Matrix Method (TMM), enabling us to calculate the three transmission rates T1, T2, T3 and the reflection rate R. The length and position of the resonator control the acoustic wave, achieving an acoustic switching phenomenon with important efficiency.