Patent ID: 7622665

Claim:
A filter device comprising: filter coefficient outputting means for outputting a set of filter coefficients; and filter means for providing filter processing based on filter characteristics determined by the set of filter coefficients outputted from the filter coefficient outputting means for a musical sound signal having a given frequency supplied from the outside; wherein the filter coefficient outputting means comprises: a parameter table having a first memory storing a plurality of sets of filter coefficients in the filter means that are associated with a first parameter based on each of a plurality of frequencies and a second parameter based on each of a plurality of levels representing a degree of attenuation or enhancement of a gain of a filter in the filter characteristics; and filter coefficient generating means for extracting a relevant set of filter coefficients from the first memory of the parameter table using the first parameter and the second parameter determined according to the frequency and a strength of the supplied musical sound signal, and for outputting the extracted set of filter coefficients to the filter means, wherein the parameter table stores a set of filter coefficients based on each set composed of each first parameter and a plurality of second parameters with a maximum level different from each other for each of a plurality of first parameters in order to obtain the filter characteristics in which the attenuation or the enhancement is realized with an almost constant slope from a reference frequency which is determined by the frequency of the supplied musical sound signal, which rises or falls as the frequency rises and falls, and from which the attenuation or the enhancement of the filter is started, and in which the slope is increased as the strength of the supplied musical sound signal is increased, where the second parameter is a maximum level of the attenuation or the enhancement of the gain in relation to the reference frequency in a previously determined given frequency, and the first parameter is a turnover frequency as a frequency in which a level of the gain becomes a given ratio in relation to the maximum level.