A speech encoding apparatus comprising: an LPC analysis section configured to perform linear predictive analysis on an input speech signal and generate a linear predictive coefficient; an LPC encoding section configured to quantize and encode the linear predictive coefficient and output a quantized linear predictive coefficient and an encoded LPC parameter; an LPC synthesis filter configured to set the quantized linear predictive coefficient to a filter coefficient; and an excitation generation section configured to output an excitation signal input to the LPC synthesis filter; an excitation power calculation section configured to calculate power of the excitation signal, as a reference excitation power, the excitation signal of which coding distortion is at a minimum, the excitation signal being obtained by adding a random code multiplied by a random code gain and a pitch multiplied by a pitch gain; a normalized prediction residual power calculation section configured to calculate, as a reference normalized prediction residual power, a normalized prediction residual power which is calculated by the following equation, from the linear predictive coefficient output from the LPC analysis section Pz n = ∏ j = 1 M 1 − r j 2, where Pz(n) is the normalized predicted residual power of frame n; M is a prediction order; and r[j] is a j-th order reflection coefficient; and a power parameter encoding section configured to encode, as concealment processing parameters, the reference excitation power and the reference normalized prediction residual power, and output as an encoded concealment processing parameters, and a multiplexing section configured to multiplex and transmit the encoded LPC parameter of a n-th frame and an encoded excitation parameter of a n-th frame and the encoded concealment processing parameters of a (n-1)-th frame, the encoded excitation parameter of the n-th frame including a random codebook index, a random codebook gain, a pitch gain, and a pitch lag, to which the excitation signal of the n-th frame is encoded, and the encoded concealment processing parameters of the (n-1)-th frame including the reference excitation power and the reference normalized prediction residual power encoded by the power parameter encoding section. an LPC analysis section configured to perform linear predictive analysis on an input speech signal and generate a linear predictive coefficient; an LPC encoding section configured to quantize and encode the linear predictive coefficient and output a quantized linear predictive coefficient and an encoded LPC parameter; an LPC synthesis filter configured to set the quantized linear predictive coefficient to a filter coefficient; and an excitation generation section configured to output an excitation signal input to the LPC synthesis filter; an excitation power calculation section configured to calculate power of the excitation signal, as a reference excitation power, the excitation signal of which coding distortion is at a minimum, the excitation signal being obtained by adding a random code multiplied by a random code gain and a pitch multiplied by a pitch gain; a normalized prediction residual power calculation section configured to calculate, as a reference normalized prediction residual power, a normalized prediction residual power which is calculated by the following equation, from the linear predictive coefficient output from the LPC analysis section Pz n = ∏ j = 1 M 1 − r j 2, where Pz(n) is the normalized predicted residual power of frame n; M is a prediction order; and r[j] is a j-th order reflection coefficient; and Pz(n) is the normalized predicted residual power of frame n; M is a prediction order; and r[j] is a j-th order reflection coefficient; and a power parameter encoding section configured to encode, as concealment processing parameters, the reference excitation power and the reference normalized prediction residual power, and output as an encoded concealment processing parameters, and a multiplexing section configured to multiplex and transmit the encoded LPC parameter of a n-th frame and an encoded excitation parameter of a n-th frame and the encoded concealment processing parameters of a (n-1)-th frame, the encoded excitation parameter of the n-th frame including a random codebook index, a random codebook gain, a pitch gain, and a pitch lag, to which the excitation signal of the n-th frame is encoded, and the encoded concealment processing parameters of the (n-1)-th frame including the reference excitation power and the reference normalized prediction residual power encoded by the power parameter encoding section.