A multi-channel
signal generator (200) is provided for generating a multi-channel
signal (204) having a first channel (201) and a second channel (203). The multi-channel
signal generator (200) includes: a first audio source (211) for generating a first
audio signal (221); a second audio source (213) for generating a second
audio signal (223); a
mixed noise source (212) for generating a
mixed noise signal (222); and a mixer (206) for mixing the
mixed noise signal (222) with the first
audio signal (221) to obtain the first channel (201), and mixing the mixed
noise signal (222) with the second audio signal (222) to obtain the second channel (203). The present invention also provides an audio
encoder, comprising: an activity
detector (380) for analyzing a multichannel signal (304) to determine whether a frame in a
frame sequence (381) is an inactive frame (308); and a
noise parameter
calculator (3040) for calculating first parameter
noise data (p_noise, v_v) of the first channel (301, 201) of the multichannel signal (304). m,ind ), and calculate the second parameter noise data (p_noise, v) of the second channel (303) of the multi-channel signal (320). s,ind The coherence
calculator (320) is used to calculate coherence data (404, c) indicating the coherence between the first channel (301, 201) and the second channel (303, 203) in the inactive frame (308); and the output interface (310) is used to generate an encoded multi-channel audio signal (232) having encoded audio data of the active frame (306) and first parametric noise data (p_noise, v_v) of the inactive frame (308). m,ind ), second parameter noise data (p_noise, v s,ind ), and / or a first linear combination of the first parameter noise data and the second parameter noise data and a second linear combination of the first parameter noise data and the second parameter noise data, and coherence data (c, 404).