scratch filter

scratch filter

[′skrach ‚fil·tər]
(engineering acoustics)
A low-pass filter circuit inserted in the circuit of a phonograph pickup to suppress higher audio frequencies and thereby minimize needle-scratch noise.
References in periodicals archive ?
But in some versions, cleaned up by audio engineers using scratch filters, Erdoy-an's words are largely audible.
But in some versions, corrected by audio engineers through scratch filters, Erdoy-an's words are largely audible.