Speech and audio coding using temporal masking

This paper presents a comparison of three auditory temporal masking models for speech and audio coding applications. The first model was developed based upon the existing forward masking psychoacoustic data with an assumption of ail approximately 200 ms. The model's dynamic parameters were derived from this data. The previously developed second model was,: based upon the principle of an exponential decay following higher energy stimuli, where the masking effects have a relatively short duration. The existing third model best matches the previously reported forward masking, data using ail exponential curve but the effects of the Forward masking are restricted to 100-200ms. Objective assessments employing the PESQ measure reveal that these three ternporal models have potential for removing perceptually redundant information in speech and audio coding, applications. Results show that the incorporation of temporal masking along with simultaneous masking into a speech/audio coding algorithm results in a further bit rate reduction of approximately 17% compared with simultaneous masking alone. while preserving perceptual quality.