Patent ID: 8612236
Filing Date: 2013-12-17
Classification: G10L

Abstract:
1. A method for noise suppression in an audio signal having been encoded by a hybrid encoder, which produces an encoded signal, and the encoded signal having been decoded by a hybrid scalable decoder, the noise suppression comprising: (a) determining from a first decoded signal contribution a first energy envelope, the first decoded signal contribution provided by the hybrid scalable decoder having decoded a first signal contribution of the encoded signal into the first decoded signal contribution; (b) determining from a second decoded signal contribution a second energy envelope, the second decoded signal contribution provided by the hybrid scalable decoder having decoded a second signal contribution of the encoded signal into the second decoded signal contribution; (c) forming a ratio from a relationship between the first and the second energy envelopes; (d) deriving a gain factor based on the ratio; and (e) multiplying the second decoded signal contribution by the gain factor when the ratio falls below a predetermined threshold value to reduce pre-echo and post-echo interference noises.