Basics of speech coding

Basics of speech coding

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  Basics of Speech Coding
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  Introduction Speech coding isthe process of obtaining a compact representation of voice signals for efficient transmission over band-limited wired and wireless channels and/or storage. Today, speech coders have become essential components in telecommunications and in the multimedia infrastructure.
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  ...continued Commercial systems thatrely on efficient speech coding include cellular communication, voice over internet protocol (VOIP), videoconferencing, electronic toys, archiving, and digital simultaneous voice and data (DSVD), as well as numerous PC-based games and multimedia applications.
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  The Art ofSpeech Coding Speech coding is the art of creating a minimally redundant representation of the speech signal that can be efficiently transmitted or stored in digital media, and decoding the signal with the best possible perceptual quality.
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  Like other continuous-timesignal Like any other continuous-time signal, speech may be represented digitally through the processes of sampling and quantization; speech is typically quantized using either 16bit uniform or 8-bit companded quantization.
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  Like many othersignals Like many other signals, however, a sampled speech signal contains a great deal of information that is either redundant (nonzero mutual information between successive samples in the signal) or perceptually irrelevant (information that is not perceived by human listeners).
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  Speech Coder A speechcoder converts a digitized speech signal into a coded representation, which is usually transmitted in frames. A speech decoder receives coded frames and synthesizes reconstructed speech. Standards typically dictate the input-output relationships of both coder and decoder.
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