A device for quantizing a gain of a fixed contribution of an excitation in a frame, including sub-frames, of a coded sound signal, comprising: an input for a parameter representative of a classification of the frame; an estimator of the gain of the fixed contribution of the excitation in a sub-frame of said frame, using the parameter representative of the classification of the frame; and a predictive quantizer of the gain of the fixed contribution of the excitation, in the sub-frame, using the estimated gain; wherein the predictive quantizer determines a correction factor for the estimated gain as a quantization of the gain of the fixed contribution of the excitation; wherein the estimated gain multiplied by the correction factor gives the quantized gain of the fixed contribution of the excitation; and wherein the estimator comprises, for a first sub-frame of the frame: (a) a first calculator of a linear estimation of the gain of the fixed contribution of the excitation in logarithmic domain in response to the parameter representative of the classification of the frame; (b) a subtractor of an energy of a filtered innovation codevector from a fixed codebook in logarithmic domain from the linear gain estimation from the first calculator, the subtractor producing a gain in logarithmic domain; (c) a converter of the gain in logarithmic domain from the subtractor to linear domain to produce the estimated gain; and (d) a multiplier of the estimated gain by the correction factor to produce the quantized gain of the fixed contribution of the excitation; and wherein the estimator, for each sub-frame of said frame following the first sub-frame, is responsive to the parameter representative of the classification of the frame and gains of adaptive and fixed contributions of the excitation of at least one previous sub-frame of the frame to estimate the gain of the fixed contribution of the excitation. an input for a parameter representative of a classification of the frame; an estimator of the gain of the fixed contribution of the excitation in a sub-frame of said frame, using the parameter representative of the classification of the frame; and a predictive quantizer of the gain of the fixed contribution of the excitation, in the sub-frame, using the estimated gain; wherein the predictive quantizer determines a correction factor for the estimated gain as a quantization of the gain of the fixed contribution of the excitation; wherein the estimated gain multiplied by the correction factor gives the quantized gain of the fixed contribution of the excitation; and wherein the estimator comprises, for a first sub-frame of the frame: (a) a first calculator of a linear estimation of the gain of the fixed contribution of the excitation in logarithmic domain in response to the parameter representative of the classification of the frame; (b) a subtractor of an energy of a filtered innovation codevector from a fixed codebook in logarithmic domain from the linear gain estimation from the first calculator, the subtractor producing a gain in logarithmic domain; (c) a converter of the gain in logarithmic domain from the subtractor to linear domain to produce the estimated gain; and (d) a multiplier of the estimated gain by the correction factor to produce the quantized gain of the fixed contribution of the excitation; and (a) a first calculator of a linear estimation of the gain of the fixed contribution of the excitation in logarithmic domain in response to the parameter representative of the classification of the frame; (b) a subtractor of an energy of a filtered innovation codevector from a fixed codebook in logarithmic domain from the linear gain estimation from the first calculator, the subtractor producing a gain in logarithmic domain; (c) a converter of the gain in logarithmic domain from the subtractor to linear domain to produce the estimated gain; and (d) a multiplier of the estimated gain by the correction factor to produce the quantized gain of the fixed contribution of the excitation; and wherein the estimator, for each sub-frame of said frame following the first sub-frame, is responsive to the parameter representative of the classification of the frame and gains of adaptive and fixed contributions of the excitation of at least one previous sub-frame of the frame to estimate the gain of the fixed contribution of the excitation.