Patent ID: 6356872
Filing Date: 2002-03-12
Classification: G10L

Abstract:
A digital audio system for storing digital audio data on a digital audio media as stored audio information and retrieving the stored digital audio data in a playback operation, comprising:a first date conversion device for converting an audio input signal to a digital audio signal with a noise response at a first sampling rate and at a first word length and operating over an associated frequency band; a noise shaping device for noise shaping the noise response of the digital audio signal to shift noise from a low portion of the frequency band thereof to a higher portion of the frequency band thereof; an output device for outputting the noise shaped digital audio signal to the digital audio media for storage thereon; an access device for retrieving the stored noise shaped digital audio signal from the digital audio media; and a second data conversion device for converting the retrieved noise shaped digital audio signal to an audio signal such that the noise shifted to the higher portion of the frequency band is not in the audible range, said second data conversion device including a low pass filter for low pass filtering the retrieved noise shaped digital audio signal at a word length greater than said first word length to remove noise in the higher portion of the frequency band of the digital audio signal in addition to the associated audio signal thereat wherein a sharpness of the low pass filter is reduced by extending a passband attenuation of the low pass filter so that fewer taps are required for the low pass filter.