Phonon and the coupling to electrons

I am new to looking at phonons, especially in relation to their use in coupling to electrons. Phonons can be defined as the treatment of vibrations in a crystal lattice. There can be different types/modes of phonons such as acoustic (longitudinal and transverse), long-wavelength, optical phonons and im sure there are many more. I see for a particle material a phonon has a dispersion $\omega(\vec{q})$ often shown over the reduced Brillouin zone which can include say, 12 different modes of phonon each of which corresponds to a dispersion 'line' in the obtained plot. My question is, if one is to look at how to couple the phonon to say an electron in the conduction band does one need to look and obtain contribution from all the phonon modes or are there approximations to choosing which is most suitable for the greater contributions.