A non-uniform modulation transform for audio coding with increased time resolution

Perceptual audio coders exploit two properties to achieve coding gain: perceptual irrelevancy and source redundancy. Recently, a two-dimensional modulation transform was introduced which efficiently extracts perceptual irrelevancy and source redundancy not accessible in a one-dimensional transform. In this paper, we propose an alternative modulation transform design with an octave-band non-uniform modulation dimension. This non-uniform modulation dimension approximately mimics the spacing of modulation filter subbands of the human auditory system, while simultaneously increasing the time resolution of the modulation transform providing improved temporal control of coding noise.