The temperature dependence of the dephasing rates of M1 and M2 reflects differences of their involvement in multi-phonon interactions. While one can fit the experimental dynamics to sev- eral damped oscillators to estimate the coherence lifetimes of each of the modes, large number of fit parameters and possible energy shifts that cannot be rigorously accounted for make the fitting routine unreliable. We instead implement a continuous wavelet transform (CWT) approach based on a complex Morlet wavelet (the details are presented in ESI † ) to analyze and visualize the coherence evolution in time for each of the individual modes. The wavelet transformation decomposes the impulsive oscillatory signals allowing time-frequency visualization. This was described in detail by Staszewski for simulated examples of multicomponent impulsive responses . Briefly, the CWT transform of an oscillatory function generates two-dimensional spectra, shown in Fig. for selected temperatures, where the normalized amplitude is plotted as a function of the beating energy and the pumpprobe delay; the complete temperature dependence can be found in the ESI † . The amplitude of the observed modes represents the modulation depth in the differential transmission experiment and correlates directly with the intensity of the RISRS spectrum of Fig. ). We observe that, for all observed modes, it decays in tens of picoseconds at all temperatures.