Filter material: layer of fine gravel used in slope stabilization structures that allows water to escape and retains soil particles.

UNESCO: L O S S A R Y

Another has perfectly arrayed pores 3 nanometers across, a mesh so fine it is used to filter individual amino acids in the DNA sequencing process.

FORBES: The Science of Small

In humans the vocal tract acts as a filter on the sound from the source, and the "source-filter theory" held that the separate, fine control of the vocal tract to be the product of a long evolution in the development of the subtleties of speech.

BBC: Helium-huffing gibbons 'sing with soprano technique'