  Recently, it has been predicted that the Berry curvature of electrons can
produce an angular momentum for phonons. In systems with time-reversal
symmetry, the direction of the phonon angular momentum is locked to the phonon
wave vector. Accordingly, this phenomenon has received the name of ``phonon
helicity". Here, we present a theory to unveil the signatures of such phonon
helicity using Raman scattering. We show that the intensity of Raman scattering
for circularly polarized light in BaMnSb$_2$ (a prototypical nonchiral Dirac
insulator) changes under a reversal of the phonon wave vector, and that the
phonon helicity can be inferred from that change. We compare our results to
recent reports of Raman-based detection of phonon angular momentum in chiral
crystals.
