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Audio data compression

In principle, the audio engineering problem presented by low-data bandwidth, and therefore in reduced digital resolution, is no different to the age-old analogue problem of restricted dynamic range. In analogue systems, noise reduction systems (like Dolby B or dbx1) have been used for many years to enhance the dynamic range of inherently noisy transmission systems like analogue tape. All of these analogue systems rely on a method called ‘compansion’, a word derived from the contraction of compression and expansion, which refers to the dynamic range being deliberately reduced (compressed) in the recording stage processing and recovered (expanded) in the playback electronics. In some systems this compansion acts over the ...

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