apparatus and methods for enhancing an electronic audio signal by adding enhancing harmonics to the electronic audio signal . the present invention includes a field inducing coil through which input electronic audio signals are to be transmitted to set up an electromagnetic field . the field inducing coil is weakly coupled to an electromagnetic field receptor such that when an input electronic audio signal is transmitted through the inducing coil only a small portion of the electromagnetic field cuts or passes through the field receptor in order to produce an induced electronic audio signal having a greater harmonic content than the input electronic audio signal .