function y=two_power(signal, gain, bias, mix)
i1 = signal*gain; %multiply the amplitude of the input signal by the value
%of the gain variable.
i2 = sin(i1) + (abs(sin(i1))).^2 - bias; %apply the equation to the 
%amplified input signal
i3 = mix*i2+(1-mix)*signal; % blend original signal with processed signal
y = i3./max(abs(i3));% normalize output amplitude so that the maximum 
%amplitude is 1.
end
