A speech coder equipped with a digital speech coder and a digital speech decoder decodes a compressed digital speech data strip that is decompressed to synthesize digital output speech samples by using fast excitation coding to reduce the computational power needed to compress the digital samples of the input speech signal. Generates. Many fast excitation codings are provided by the excitation search device of the encoder. The search device determines excitation information that defines an aperiodic group of excitation pulses. The optimal position of each pulse of the aperiodic pulse group is selected from the corresponding set of pulse positions stored in the encoder. The searcher determines the optimal pulse position by maximizing the correlation between (a) the target group of the filtered version of the digital speech sample provided to the encoder for compression and (b) the corresponding group of synthesized digital speech samples. The synthesized group of samples depends on the pulse position used in the corresponding set of stored pulse positions and the sign of Pals at that pulse position.
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