The influence of bulk acoustic wave excitation in langasite crystal on Raman spectra was studied. It was found that acoustic wave propagating in the crystal volume changes the intensity and position of the Raman scattering lines. Under bulk acoustic wave propagation conditions, Raman peak intensity changes less on 5% and peak position shifts on 0.5 cm-1. To detect such small changes, principal component analysis of Raman spectra was used.