The paradigm of cosmic inflation explains our observations of the cosmic microwave background spectacularly well. To proceed in the quest of pinning down the particle physics model behind this very early phase of the Universe, multi-wavelength observations of the power spectra of the anisotropies generated during cosmic inflation are crucial. If the inflaton is a pseudo-Goldstone boson (a possible explanation for the required flatness of the inflaton potential), the couplings of this inflaton to the Standard Model may provide a window to probe inflation over a very wide range scales: as I will argue in this talk, different plausible couplings to gauge fields and fermions lead to unique signatures in the scalar and tensor power spectra at small scales. I will discuss possibilities to probe these scales, with a special focus on gravitational wave observatories.