Patent ID: 7356150
Filing Date: 2008-04-08
Classification: G10L

Abstract:
1. An audio signal band extending apparatus comprising: a noise generating device for generating a noise signal level-correlated to and so as to change according to one of a level of an inputted signal and a level of a signal in a partial band obtained by bandpass-filtering the inputted signal using a bandpass filtering device; a signal processing device for multiplying a generated noise signal by a predetermined transfer function so that, at a lower limit frequency of a predetermined band-extended signal, a level of the generated noise signal substantially coincides with the level of the inputted signal and a spectral continuity thereof is kept when addition is executed by an adding device, and for outputting a signal having a multiplication result; and an adding device for adding up the inputted signal and an outputted signal from said signal processing device, and for outputting a signal having an addition result, wherein said noise generating device comprises: a level signal generating device for detecting a level of a signal inputted to said noise generating device, and for generating and outputting a level signal having a detected level; a noise signal generating device for generating and outputting a noise signal according to the signal inputted to said noise generating device; and a multiplying device for multiplying the level signal from said level signal generating device by the noise signal from said noise signal generating device, and for outputting a noise signal having a multiplication result.