A frequency-domain noise shaping method for interpolating a spectral shape and a time-domain envelope of quantization noise in a windowed and MDCT transform-coded audio signal, characterized in that it comprises: processing quantized spectral bands ( C 1f [k], C 2f [k], C 3f [k],..., C Mf [k]) of the windowed and MDCT transform-coded audio signal through respective inverse filters ( Inverse Filter 1, Inverse Filter 2, Inverse Filter 3,..., Inverse Filter M) to produce decoded spectral bands ( C 1 [k], C 2 [k], C 3 [k],..., C M [k]); concatenating the decoded spectral bands ( C 1 [k], C 2 [k], C 3 [k],..., C M [k]) to produce decoded spectral coefficients ( Y[k]); and inverse MDCT transforming the decoded spectral coefficients (Y[k]) to produce a decoded block of time-domain samples (y[n]) of the audio signal; - wherein processing the quantized spectral bands ( C 1f [k], C 2f [k], C 3f [k],..., C Mf [k]) comprises, for each quantized spectral band ( C 1f [k], C 2f [k], C 3f [k],..., C Mf [k]): calculating noise gains g 1 [m] and g 2 [m] representing spectral shapes of the quantization noise respectively at a middle point of a first overlap between a current MDCT transform-processing overlapping window (window 1) and a preceding MDCT transform-processing overlapping window (window 0) and at a middle point of a second overlap between the current MDCT transform-processing overlapping window (window 1) and a subsequent MDCT transform-processing overlapping window (window 2); and filtering quantized spectral coefficients ( Y f [k]) of the quantized spectral band using the following first-order recursive filter: C m k = aC mf k + bC m k − 1 where a and b are filter parameters and m identifies the spectral band, and where a = 2(( g 1 [ m] g 2 [ m])/( g 1 [ m]+ g 2 [ m])) b = (( g 2 [ m]- g 1 [ m])/( g 1 [ m]+ g 2 [ m])) processing quantized spectral bands ( C 1f [k], C 2f [k], C 3f [k],..., C Mf [k]) of the windowed and MDCT transform-coded audio signal through respective inverse filters ( Inverse Filter 1, Inverse Filter 2, Inverse Filter 3,..., Inverse Filter M) to produce decoded spectral bands ( C 1 [k], C 2 [k], C 3 [k],..., C M [k]); concatenating the decoded spectral bands ( C 1 [k], C 2 [k], C 3 [k],..., C M [k]) to produce decoded spectral coefficients ( Y[k]); and inverse MDCT transforming the decoded spectral coefficients (Y[k]) to produce a decoded block of time-domain samples (y[n]) of the audio signal; - wherein processing the quantized spectral bands ( C 1f [k], C 2f [k], C 3f [k],..., C Mf [k]) comprises, for each quantized spectral band ( C 1f [k], C 2f [k], C 3f [k],..., C Mf [k]): calculating noise gains g 1 [m] and g 2 [m] representing spectral shapes of the quantization noise respectively at a middle point of a first overlap between a current MDCT transform-processing overlapping window (window 1) and a preceding MDCT transform-processing overlapping window (window 0) and at a middle point of a second overlap between the current MDCT transform-processing overlapping window (window 1) and a subsequent MDCT transform-processing overlapping window (window 2); and filtering quantized spectral coefficients ( Y f [k]) of the quantized spectral band using the following first-order recursive filter: C m k = aC mf k + bC m k − 1 - wherein processing the quantized spectral bands ( C 1f [k], C 2f [k], C 3f [k],..., C Mf [k]) comprises, for each quantized spectral band ( C 1f [k], C 2f [k], C 3f [k],..., C Mf [k]): calculating noise gains g 1 [m] and g 2 [m] representing spectral shapes of the quantization noise respectively at a middle point of a first overlap between a current MDCT transform-processing overlapping window (window 1) and a preceding MDCT transform-processing overlapping window (window 0) and at a middle point of a second overlap between the current MDCT transform-processing overlapping window (window 1) and a subsequent MDCT transform-processing overlapping window (window 2); and filtering quantized spectral coefficients ( Y f [k]) of the quantized spectral band using the following first-order recursive filter: C m k = aC mf k + bC m k − 1 calculating noise gains g 1 [m] and g 2 [m] representing spectral shapes of the quantization noise respectively at a middle point of a first overlap between a current MDCT transform-processing overlapping window (window 1) and a preceding MDCT transform-processing overlapping window (window 0) and at a middle point of a second overlap between the current MDCT transform-processing overlapping window (window 1) and a subsequent MDCT transform-processing overlapping window (window 2); and filtering quantized spectral coefficients ( Y f [k]) of the quantized spectral band using the following first-order recursive filter: C m k = aC mf k + bC m k − 1 where a and b are filter parameters and m identifies the spectral band, and where a = 2(( g 1 [ m] g 2 [ m])/( g 1 [ m]+ g 2 [ m])) b = (( g 2 [ m]- g 1 [ m])/( g 1 [ m]+ g 2 [ m])) a = 2(( g 1 [ m] g 2 [ m])/( g 1 [ m]+ g 2 [ m])) b = (( g 2 [ m]- g 1 [ m])/( g 1 [ m]+ g 2 [ m]))