Audio encoding device and audio encoding method

Capable of the stereo sound signal generating single suitable for signal, so restraining voice decoder device of the single a signal decoder power reducing. The single a signal generating unit of the device (101); the lock the predictive parsing unit (201) and double-function prediction parameter; the prediction parameter with 2ch voice signal of based on 1ch voice signal detention differential and oscillation amplitude; The middle prediction parameter generating unit (202) and double-function prediction parameter the middle parameter (is mounted the prediction parameter), such as a single a signal according to the terminal and 1ch voice signal and signal of 2ch voice signal; Single a signal computing unit (203) is the middle prediction parameter calculating the single a signal.