VOICE ENCODING AND DECODING DEVICE

摘要

PROBLEM TO BE SOLVED: To effectively and dynamically use frequencies by paying attention to the environment of the communication place of a mobile communication terminal to which a voice encoding system is applied and making good use of the margin of an information transmission amount obtained when a communication is made from a place where background noise is small. SOLUTION: A voice encoder decoder 15 is previously equipped with encoding and decoding functions of >=2 kinds of algorithm differing in encoded data amount. The level of a transmit signal is monitored at the output terminal of an AD converter 3 and a level detector 17 detects the background noise and the level of environmental sound in a short section from line connection to the start of a talk; and a controller 18 performs switching control so that the voice encoder decoder 15 encodes data by the algorithm having the smaller encoded data amount.