For　flow　noise　simulations,　the　nonreflecting　boundary　condition　(NRBC)　is　significant　to　confine　the　computational　domain　to　a　small　domain.　Lattice　Boltzmann　method　(LBM)　has　advantages　for　noise　because　of　its　low　dissipation,　but　is　limited　to　the　uniform　grid.　In　this　paper,　an　absorbing　boundary　condition　(ABC)　based　on　perfectly　matched　layer　(PML)　technique　is　introduced　to　LBM.　Then　PML　stability　is　analyzed　and　a　new　strategy　is　developed　to　achieve　robustness.　Invoking　the　decoupling　time　integration,　the　underlying　equation　for　streaming　is　solved　with　the　nodal　discontinuous　Galerkin　method.　Benchmark　acoustic　problems　were　used　to　demonstrate　the　PML　absorption.　Moreover,　PML　parameters,　long　time　behavior　and　inhomogeneous　pseudo　mean　flow　are　discussed.　The　methodology　appears　to　work　very　well　and　would　be　hoped　for　practical　flow　noise　computation.