APPARATUS FOR AND METHOD OF SPEECH DIGITIZING

摘要

A speech encoder converts analog speech signals into a stream of binary coded speech samples. A circuit for performing analog to digital conversion compares an input speech signal with a signal from a digital integrator. Based on the comparison a series of decisions are registered which indicate a step sign of the input signal. A syllabic filter generates a step magnitude according to the registered decisions. The step sign and step magnitude are combined providing a sign/magnitude representation of the input signal. When the sign/magnitude representation is integrated digitally in a decimation filter a digital representation of the analog signal is formed. A speech decoder, the antithesis of the encoder, converts binary coded speech samples into an analog waveform in a manner opposite to the A/D conversion method.