The perception of nonlinear distortions of audio devices, in particular the perception of nonlinear distortions of digital audio, is only insufficiently described by typical measures like THD. To provide a better insight into perceptual effects of nonlinear distortions, their audibility and the impact on psychoacoustical measures like loudness and sharpness is examined. For this purpose a test method has been developed. The first step in the test is the measurement of the frequency response of the device under test with an efficient method to enable the separation of linear and nonlinear processing. The second step of the test consists of the computation of the psychoacoustical measures and the thresholds for the audibility of nonlinear distortions. Both computations are based on the same psychoacoustical model to obtain consistent results. Results for several types of distortion obtained with simulations and measurements on analog circuits are presented.
展开▼
