Background, Motivation and Objective Perturbations in the boundary conditions of Surface Acoustic Wave (SAW) devices are typically quantified through the use of frequency-domain methods, where the device is incorporated as the feedback element in a closed-loop oscillator.While simple in implementation the closed-loop method is inherently limited to tracking a single acoustic mode and discards useful information from the time-domain.This work considers an alternative approach using transient analysis with time-frequency methods to track multiple acoustic modes simultaneously and provide additional metrics for analysis which may be significantly advantageous for many chemical sensing applications.