  Weyl points (WPs) are isolated degeneracies carrying quantized topological
charges, and are therefore robust against Hermitian perturbations. WPs are
predicted to spread to the Weyl exceptional rings (WERs) in the presence of
non-Hermiticity. Here, we use a one-dimensional (1D) Aubry-Andre-Harper (AAH)
model to construct a Weyl semimetal in a 3D parameter space comprised of one
reciprocal dimension and two synthetic dimensions. The inclusion of
non-Hermiticity in the form of gain and loss produces a WER. The topology of
the WER is characterized by both its topological charge and non-Hermitian
winding numbers. The WER is experimentally observed in a 1D phononic crystal
with the non-Hermiticity introduced by active acoustic components. In addition,
Fermi arcs are observed to survive the presence of non-Hermitian effect. We
envision our findings to pave the way for studying the high-dimensional
non-Hermitian topological physics in acoustics.
