Patent ID: 7003358

Claim:
An audio signal processor which modifies audio signal components not only in the conventional audio frequency band but also in the range of frequencies from about the upper limit of the conventional audio band to greater than 24 kHz; whereby the audio signal processor comprises a Delta Sigma Modulator (DSM) that receives a non-interpolated digital audio signal sampled at a frequency of at least 198 kHz; wherein the audio components are converted to 1-bit signals using a sampling rate in the range 198 kHz to about 2.85 MHz; wherein said DSM is a one bit DSM for modifying the signal components; and wherein the said DSM is an nth-order (where n is greater than or equal to 1) Delta Sigma Modulator (DSM) having an input for receiving a first 1-bit signal, a quantizer for requantizing a p bit signal to 1-bit from the requantized signal being the output signal of the processor, a plurality of signal combiners including a first combiner for forming an integral of an additive combination of the product of the first signal and a first coefficient coefficient and of the product of the output signal and a second coefficient, at least one intermediate combiner for forming an integral of an additive combination of the product of the first signal and a first coefficient and of the product of the second signal and the output signal and of the integral of the preceding stage, and a final combiner for forming an additive combination of the product of the first signal and a first coefficient and of the integral of the preceding stage to form the said p bit signal which is requantized by the quantizer.