Patent ID: 7647222

Claim:
A hardware apparatus for encoding digital audio data with a reduced bit rate, comprising: a provider of psycho-acoustically quantized digital audio data with a bit rate being higher than the reduced bit rate, wherein the provider includes a noise substitution process for replacing spectral data in a pre-selected frequency band by an inserted parameter of the noise substitution process, the pre-selected frequency bands being identified by a pre-selection criterion, the noise substitution process being carried out instead of psycho-acoustically quantizing the digital audio data, wherein the provider includes a pre-analyzer for analyzing digital audio data according to the pre-selection criterion for pre-selecting the frequency band for insertion of a noise substitution parameter, or a post-analyzer for analyzing psycho-acoustically quantized data in a frequency band according to the selection criterion for identifying the frequency band for psycho-acoustically quantized data replacements, wherein the pre-analyzer or the post-analyzer are operative to utilize the pre-selection criterion or the selection criterion, the pre-selection criterion being different from the selection criterion, the pre-selected frequency band being different from the identified frequency bands; an identifier for identifying the frequency band according to a selection criterion, the selection criterion being such that an impact on the quality of the digital audio data when the data in the identified frequency band is replaced by generated noise is smaller than the impact on the quality of the digital audio data, which would arise when data in a different frequency band is replaced by generated noise, and a replacer for replacing data in the identified frequency band of the digital audio data by a noise synthesis parameter, the noise synthesis parameter requiring a smaller amount of data than the data in the identified frequency band, the digital audio data comprising the reduced bit rate.