Pyrochlores exhibit a rich variety of exotic physical properties including fractionalization, topological order and emergent magnetic monopoles in the classical spin ices, and a Higgs transition to a ferromagnetic phase for their quantum analogues. The magnetic ground states of these systems are strongly sample dependent, suggesting a key role for defects. Understanding the phonons allows us to predict stable defect structures and model the strain-field relaxation around defects. The absence of a complex magnetic ground state in yttrium titanate greatly simplifies density-functional calculations, and here we propose to test our lattice dynamics model using inelastic neutron scattering.