Encoding apparatus, decoding apparatus, and method, a program, a recording medium

While suppressing the overall increase in the code amount as to provide a technique for accurately encoding and decoding can be converted coefficient to the linear prediction coefficients for the frame variation of the spectrum is large. Encoding apparatus corresponds to a plurality following the first encoding unit which can be converted coefficient to the linear prediction coefficients obtain a first code by coding, (A-1) can be converted coefficient to multiple-order LPC coefficients If the index Q corresponding to the magnitude of the peaks and valleys of the spectral envelope that is the predetermined threshold value Th1 or more, and / or, (B-1) index Q 'is a predetermined threshold value Th1 corresponding to the peaks and valleys of the smallness of the spectral envelope If 'or less, and a second encoding unit for obtaining a second code by encoding the quantization error of at least a first encoding unit.