An Audio Distortion Dynamic Range Index for Evaluating the Performance of Audio Systems

Abstract

The dynamic range (DR) index lacking of an official definition leads to ambiguities in performance evaluation. The existing measurement methods of DR do not always match with the various actual application conditions, and some detailed distortion behavior of the device under test (DUT) is not extracted. In this paper, a new index for evaluating the DR performance of audio systems is proposed and validated, herein referred to as the audio distortion dynamic range (ADDR). It reduces the uncertainty of measurement conditions by an explicit definition and unifies the signal-to-noise ratio (SNR) and the signal-to-noise-and-distortion ratio (SINAD) indexes if under the same measurement condition. Moreover, to comprehensively reflect the impact of harmonic, spurious, and noise components on the DUT, the definitions of the traditional indexes based on classification of distorted components are replaced by the variable thresholds in the ADDR definition. Subsequently, the detailed steps of ADDR and the critical factors influencing its accuracy, are analyzed and then the optimized measurement conditions are given. Experiments based on simulated DUTs show the ADDR index can distinguish performance difference that the traditional indexes cannot distinguish, which proves it is an effective supplementary to the existing indexes in some real applications.

Design of an Audio Compressor with Digital Control

“…In sound engineering, compression is a phenomenon which can be approached from the physical mechanisms of the sound particles that experiment compression and rarefaction while propagating in the acoustic mechanical wave [1]; or, a phenomenon observed in audio coding technologies related to the perceptual procedures to minimize a file volume in order to facilitate transmission and storage purposes [2], as well as its evaluation [3]; or in the HW design, a device which limits the dynamic range of an audio signal [4].…”