Phonons propagate without problems in a lattice, until they scatter on something, like a defect, an electron, or another phonon. But in a typical solid at room temperature, how much (or how long) is the mean free path of a phonon? I know that depending on the temperature one type of scattering can be more probable than the other, but do mean free paths of these different types of scattering tend to be very different from each other? (With different orders of magnitude?)