SPEECH AUDIO ENCODING DEVICE, SPEECH AUDIO DECODING DEVICE, SPEECH AUDIO ENCODING METHOD, AND SPEECH AUDIO DECODING METHOD

By the present invention, the number of encoding bits allocated to encoding of extended-band spectrum is reduced while degradation of sound quality in the extended band is suppressed. A band compression unit (105) creates combinations of sub-band spectra in pairs of two samples each in order from a low-range side in a band compression target sub-band, selects a spectrum having a large absolute-value amplitude among the combinations, and arranges the selected spectrum close to the low-range side on a frequency axis. A number-of-units recalculation unit (106) redistributes bits saved in the sub-band for which band compression was performed to a low range outside the extended band, and redistributes the number of units on the basis of the redistributed bits.