  Magnetic materials with pyrochlore crystal structure form exotic magnetic
states due to the high lattice frustration. In this work we follow the effects
of coupling of the lattice and electronic and magnetic degrees of freedom in
two Praseodymium-based pyrochlores Pr$_2$Zr$_2$O$_7$ and Pr$_2$Ir$_2$O$_7$. In
both materials the presence of magnetic interactions does not lead to
magnetically ordered low temperature states, however their electronic
properties are different. A comparison of Raman phonon spectra of
Pr$_2$Zr$_2$O$_7$ and Pr$_2$Ir$_2$O$_7$ allows us to identify magneto-elastic
coupling in Pr$_2$Zr$_2$O$_7$ that elucidates its magnetic properties at
intermediate temperatures, and allows us to characterize phonon-electron
coupling in the semimetallic Pr$_2$Ir$_2$O$_7$. We also show that the effects
of random disorder on the Raman phonon spectra is small.
