Patent ID: 8433077

Claim:
A noise removal device for removing noise included in an input signal, the noise removal device comprising: a noise detector that detects noise in the input signal and outputs a noise detection signal; an interpolation controller that determines a period an amount of interpolation for a noise correction processing, based on the input signal and the noise detection signal; and a noise gate processor that performs the noise correction processing on the input signal, based on the interpolation period and the interpolation amount supplied from the interpolation controller, wherein the interpolation controller sets a predetermined first interpolation period as the interpolation period, based on a first noise detection signal inputted from the noise detector, and redefines a second interpolation period longer the first interpolation period as the interpolation period when a second noise detection signal is detected within the first interpolation period, wherein the interpolation controller includes: a gate signal elongating unit that generates a noise gate signal for the first interpolation period by elongating the noise detection signal; a noise interval detector that detects output of the second noise detection signal within the first interpolation period, and outputs a noise interval detection signal; an interpolation amount calculator that calculates an amount of interpolation for noise correction within the first interpolation period by using a linear interpolation scheme; and an interpolation scheme selector that selects any one of the linear interpolation scheme and a previous-value hold scheme depending on the noise interval detection signal, and the interpolation scheme selector selects the linear interpolation scheme when not receiving the noise interval detection signal, and selects the previous-value hold scheme when receiving the noise interval detection signal, and wherein upon receipt of the noise interval detection signal, the gate signal elongating unit generates the noise gate signal for the second interpolation period by extending the first interpolation period.