Dynamic range compression of audio signals consistent with recent time-varying loudness models

Dynamic range compression may be used to increase the volume of the softer passages of an audio signal relative to its louder portions, thus making the signal better suited to transmission through, or storage on, a given medium. The level-detection characteristics of typical contemporary dynamic range compressors are analyzed and investigated, thus revealing the shortcomings of such models in the light of knowledge about steady-state and time-varying loudness as perceived by the human auditory system. The design of an equal-loudness filter, desired to improve the steady-state properties of compressor level detection, is presented. Finally, the time-varying properties of the level detection scheme presented, configured via attack and release times, are tuned to provide optimal correspondence with a recently proposed model of time-varying loudness.