Patent ID: 7233833
Filing Date: 2007-06-19
Classification: H03G,H04R,H04S

Abstract:
1. A method of modifying low frequency components of a digital audio signal having left and right channel signals, the method comprising the steps of: a) filtering the left and right channels signals using respective left and right high-pass filters to form left and right high-pass filtered signals; b) filtering the left and right channel signals using respective left and right band-pass filters to form left and right low frequency signals; c) modifying the amplitude of the left and right low frequency signals to give modified left and right low frequency signals whereby signals with amplitude a where 0<a<a 1 are amplified by a first constant value C 1 , signals with amplitude a 1 ≦a <a 2 are amplified proportional to 1/a, signals with amplitude a≦a 2 are unchanged, signals with amplitude a 2 <a<a 3 are attenuated proportional to 1/a, and signals with amplitude a=a 3 are attenuated by a second constant value C 2 ; and d) combining the modified band-pass filtered left and right signals with the respective left and right high-pass filtered signals to form respective modified left and right channel audio signals.