Various methods of producing sound from 'sounding' sand in the laboratory are explored. Low amplitude sound with frequency similar to that of 'booming' during spontaneous avalanches was produced in a small inclined chute and rotating flask. Shearing of dried sand with a stylus, and pouring from buckets or shaking in a jar produced loud sound in 200-500Hz range. Dryness of the sand and flowrate have significant effect on the produced sound. A model based on kinetic theory is proposed to explain the production of oscillations in avalanching flows. The avalanching layer behaves like a breathing mode with infinite wavelength, and perturbations in volume fraction allow oscillatory behaviour to be sustained in the inclined shear flow. Finally, a phase transition model is used to explain the presence, and characteristics, of oscillations observed in numerical simulations of inclined flows near their stopping angle.