A.1     Introduction          
        A.2     Description of the VAD    
                  A.2.1     Adaptation enable flag computation          
                  A.2.2     Inverse filtering     
                  A.2.3     Filtered energy computation         
                  A.2.4     Noise level computation   
                  A.2.5     Threshold computation     
                  A.2.6     The VAD decision           
                  A.2.7     VAD hangover addition   
                  A.2.8     VAD initialization 
        A.3     General description of the CNG    
        A.4     Description of the CNG encoder part        
                  A.4.1     Computation of the frame autocorrelation function 
                  A.4.2     Computation of the current frame type Ftypt         
                  A.4.3     Quantization of the average energy           
                  A.4.4     Computation and coding of SID parameters         
                  A.4.5     Computation of the CNG excitation          
                  A.4.6     Interpolation of LSPs and update 
                  A.4.7     COD-CNG initialization   
        A.5     Description of the decoder part     
                  A.5.1     Description of DEC-CNG           
                  A.5.2     Frame erasure concealment with regards to the CNG       
                  A.5.3     DEC-CNG initialization    
        A.6     Bit stream packing
        A.7     Glossary
        A.8     Bit-exact, fixed-point C source code