Adaptive diffuse signal generation in an upmixer

An apparatus, comprising:

• an interface system;
• and
• a logic system capable of:
• receiving, via the interface system, N input audio signals, wherein each of the N audio signals corresponds to a spatial location;
• deriving diffuse portions of the N audio signals;
• detecting instances of transient audio signal conditions;
• and
• processing the diffuse portions of the N audio signals to derive M diffuse audio signals, wherein M is greater than N and is greater than 2, and wherein during instances of transient audio signal conditions the processing comprises distributing the diffuse portions of the N audio signals in greater proportion to one or more of the M diffuse audio signals corresponding to spatial locations relatively nearer to the spatial locations of the N audio signals and in lesser proportion to one or more of the M diffuse audio signals corresponding to spatial locations relatively further from the spatial locations of the N audio signals.

A non-transitory medium having software stored thereon, the software including instructions for controlling at least one apparatus to:

• receive N input audio signals, wherein each of the N audio signals corresponds to a spatial location;
• derive diffuse portions of the N audio signals;
• detect instances of transient audio signal conditions;
• and
• process the diffuse portions of the N audio signals to derive M diffuse audio signals, wherein M is greater than N and is greater than 2, and wherein during instances of transient audio signal conditions the processing comprises distributing the diffuse portions of the N audio signals in greater proportion to one or more of the M diffuse audio signals corresponding to spatial locations relatively nearer to the spatial locations of the N audio signals and in lesser proportion to one or more of the M diffuse audio signals corresponding to spatial locations relatively further from the spatial locations of the N audio signals.