Claims
- 1. A filter for generating a sequence of output values in discrete time from a sequence of input values comprising:
- a direct-form filter controlled by a plurality of filter coefficients;
- a means for generating said filter coefficients as polynomial functions of a damping parameter signal and a frequency parameter signal by implementing multipliers and adders to combine said damping and frequency parameter signals, wherein said damping parameter signal and said frequency parameter signal are independently adjustable.
- 2. The filter of claim 1, wherein said generating means determines said coefficients comprising values (-2+2df+f.sup.2) and (1-2df) from said damping and said frequency parameters.
- 3. The filter of claim 1, wherein said generating means determines said coefficients comprising values (-2+2df+f.sup.2 -d.sup.2 f.sup.2) and (1-2df+d.sup.2 f.sup.2) from said damping and said frequency parameters.
- 4. The filter of claim 1, wherein said generating means determines said coefficients comprising values (-2+2df+f.sup.2 -d.sup.2 f.sup.2 -df.sup.3 /2f.sup.4 /16) and (1-2df+d.sup.2 f.sup.2) from said damping and said frequency parameters.
- 5. The filter of claim 1, wherein said generating means determines said coefficients which comprise (-2+2df+f.sup.2 -2d.sup.2 f.sup.2 +d.sup.3 f.sup.3 -f.sup.4 /16-df.sup.3 /2+cd.sup.2 f.sup.4) and (1-2df+2d.sup.2 f.sup.2 -d.sup.3 f.sup.3) from said damping and said frequency parameters and wherein said coefficient c ranges from zero to 0.25.
- 6. In a filter, a method of generating a sequence of output values in discrete time comprising the steps of:
- providing at least one damping parameter signal;
- providing at least one frequency parameter signal wherein said frequency parameter signal and said damping parameter signal are independently adjustable;
- controlling a direct form filter according to a plurality of filter coefficients;
- generating said filter coefficients as polynomial functions of said damping and frequency parameter signals by factoring said damping and frequency parameter signals into said direct form filter.
- 7. The method of claim 6, wherein said coefficients comprise values -2+2df+f.sup.2 and 1-2df.
- 8. The method of claim 6, wherein said coefficients comprise values -2+2df+f.sup.2 -d.sup.2 f.sup.2 and 1-2df+d.sup.2 f.sup.2.
- 9. The method of claim 6, wherein said coefficients comprise values -2+2df+f.sup.2 -d.sup.2 f.sup.2 -df.sup.3 /2-f.sup.4 /16 and 1-2df+d.sup.2 f.sup.2.
- 10. The method of claim 6, wherein said coefficients comprise values -2+2df+f.sup.2 -2d.sup.2 f.sup.2 +d.sup.3 f.sup.3 -f.sup.4 /16-df.sup.3 /2+cd.sup.2 f.sup.4 and 1-2df+2d.sup.2 f.sup.2 -d.sup.3 f.sup.3.
- 11. The method of claim 10, wherein the coefficient c ranges from zero to 0.25.
- 12. A filter for generating a sequence of output values in discrete time from a sequence of input values, comprising:
- a direct form filter coupled to receive a plurality of filter coefficients; and
- a coefficient calculating circuit coupled to receive independently adjustable damping and frequency parameter signals, said coefficient calculating circuit being operative to generate said filter coefficients as a function of said damping and frequency parameter signals.
- 13. The filter of claim 12, wherein said function is a polynomial function.
- 14. The filter of claim 12, wherein said coefficient calculating circuit comprises a plurality of multipliers and adders.
Parent Case Info
This is a divisional of application Ser. No. 07/990,666, filed Dec. 14, 1992, now U.S. Pat. No. 5,355,329.
US Referenced Citations (8)
Non-Patent Literature Citations (1)
Entry |
"ASIC Implementation of the Lyon Cochlea Model" by C. D. Summerfield and R. F. Lyon, in Proc. International Conference on Acoustics, Speech, and Signal Processing, IEEE, 1992. |
Divisions (1)
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Number |
Date |
Country |
Parent |
990666 |
Dec 1992 |
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