  Chirality is an indispensable concept that pervades fundamental science and
nature, manifesting itself in diverse forms such as chiral quasiparticles and
chiral structures. Of particular interest are Weyl phonons carrying specific
Chern numbers and chiral phonons doing circular motions in crystals. Up to now,
Weyl and chiral phonons have been studied independently and the interpretations
of chirality seem to be different in these two concepts, impeding our
understanding. Here, we demonstrate that Weyl and chiral phonons are entangled
in chiral crystals. Employing a typical chiral crystal of elementary tellurium
(Te) as a case study, we expound on the intrinsic relationship between Chern
number of Weyl phonons and pseudo-angular momentum (PAM) of chiral phonons. In
light of the mutual coupling, we propose Raman scattering as a new technique to
demonstrate the existence of Weyl phonons in Te, by detecting the
chirality-induced energy splitting between the two constituent chiral phonon
branches for Weyl phonons. By using the same experimental approach, we also
observe the obstructed phonon surface states for the first time.
