The emulation of non - linearity of Musical Instruments by means of Volterra series

The measurement and emulation of musical instruments have been studies in the last decades. One of the most-used methods to obtain information about an audio system is that based on measuring its impulse response (IR). Once the IR has been caught it is possible to recreate, by the use of linear convolution, the output signal that the audio system will generate when it is physically driven by any input signal. This method gives great results if the system is linear and time-invariant, but not satisfactory in other cases, such as the emulation of sound- chests of musical instruments. By an enhanced impulse response measurement method it is possible to obtain a set of impulses and then apply Volterra series to have the output of the musical instrument driven by any source music. A special numerical tool has been developed to recreate the system behaviour by using this method. Satisfactory results have been obtained in comparison with the traditional linear convolution based approach.