Multi-channel signal generator, audio encoder and related methods relying on a mixing noise signal

An audio encoder for generating an encoded multi-channel audio signal for a sequence of frames comprising an active frame and an inactive frame, the audio encoder comprising:

• an activity detector for analyzing a multi-channel signal to determine a frame of the sequence of frames to be an inactive frame;
• a noise parameter calculator for calculating first parametric noise data for a first channel of the multi-channel signal, and for calculating second parametric noise data for a second channel of the multi-channel signal;
• a coherence calculator for calculating coherence data indicating a coherence situation between the first channel and the second channel in the inactive frame;
• and
• an output interface for generating the encoded multi-channel audio signal comprising encoded audio data for the active frame and, for the inactive frame, the first parametric noise data, the second parametric noise data, and/or a first linear combination of the first parametric noise data and the second parametric noise data and second linear combination of the first parametric noise data and the second parametric noise data, and the coherence data.