US Patent 12004923 Acoustic fluid and earplug

Systems and methods for occluding a duct and attenuating sound may be provided. In some embodiments, a device for attenuating sound passing through a duct or orifice may include a body sized and shaped to be inserted, at least partially, into a duct or orifice. The body may have an interior volume that contains a fluid suspension. In some embodiments, the fluid suspension may include a plurality of gas-filled spheres dispersed in an interstitial fluid. The gas-filled spheres may increase an acoustic attenuation of the fluid suspension relative to the interstitial fluid alone.