Speech Coding and Human Speech Perception

The subject of speech coding covers speech processing techniques for reducing the information rate to transmit a speech signal over a communication channel. The amount of information that a speech signal carries is really not known. The acoustic signal representing the sound pressure variations in front of the speaker's lips is a continuous signal whose information content, in theory, could be very large. But the capabilities of human perception are not unbounded - they are limited. Proper understanding of human auditory is vital for efficient speech coding.