Adaptive proportional gain audio mixing system

An audio mixing system comprising:

• a plurality of input channels, each said input channel comprising means for receiving an input signal;
• and means for generating an attenuated signal from said input signal, the degree of attenuation being specified by a channel control signal corresponding to said channel;
• means for combining all of said attenuated signals to form an output signal;
• and
• control means for generating said channel control signals, each said channel control signal being responsive to said input signal on said channel, said attenuated signal on said channel, and the value of a parameter x corresponding to said channel, said parameter x corresponding to each said channel defining the relative contribution of said input signal and said attenuated signal in said channel to said channel control signals, wherein said control means further comprises means for periodically selecting one of said channels, said selection depending on said parameter x, said attenuated signal, and said input signal for each said channel, over a preceeding time period and wherein said control means decreases said parameter x corresponding to said selected channel and increases said parameter x corresponding to the remaining channels provided said increases or decreases do not cause x to have a value outside a predetermined range, said increases and decreases being made in response to said periodic determination.