Engineering Brief
Nonlinear Distortion Measurement in Audio Amplifiers: The Perceptual Nonlinear Distortion Response
AES Convention 133 · Paper 69 · October 2012
Abstract
A new metric for measuring nonlinear distortion is introduced called the Perceptual Nonlinear Distortion Response (PNDR) to measure nonlinear distortion in audio amplifiers. This metric accounts for the auditory system's masking effects. Salient features of previously developed nonlinear distortion measurements are considered in the development of the PNDR. A small group of solid-state and valve audio amplifiers were subjected to various benchmark tests. A listening test was created to test perceptibility of nonlinear distortions generated in the amplifiers. These test results were analyzed and the Perceptual Nonlinear Distortion Response was more successful than traditionally used distortion metrics. This cognitive tool could provide the audio industry with more accurate test methods, facilitating product research and development.
