Patent ID: 7248702

Claim:
A system for enhancing sound quality, comprising an input terminal for receiving an input signal, a first filter that receives signal from the input terminal that blocks frequencies below a certain predetermined frequency; a complementary filter that receives signal from the input terminal, a square root filter coupled to the first filter, the circuit being configured to determine a square root of an input signal portion on a continual basis; and a differentiator whose gain increases with increasing frequency connected between said first filter and said square root filter, a summer with one input to receive signal from said complementary filter and a second input to receive signal from the square root filter and that has an output connected to an output terminal; an integrator connected between said square root filter and said one input of said summer, whereby the output signal at said output terminal is the sum of square root signal for input signals above the predetermined frequency, plus input signal for all other frequencies blocked by the first filter, and wherein when signal from said first filter comprises low frequency and high frequency signals greater than said pre-determined frequency and having similar amplitudes, said square root filter receives a relatively greater amplitude of said high frequency signal from said differentiator and is predisposed to produce artificial overtones from said high frequency, and wherein said integrator provides an inverse gain versus frequency relationship to said differentiator.