diff --git a/lib_dec/acelp_core_dec_ivas_fx.c b/lib_dec/acelp_core_dec_ivas_fx.c
index 9dbac8dd61d242323f6738c89ce48e78f9403b0c..739e4de2eabd2f2d95c1c7063ea473cc670cb319 100644
--- a/lib_dec/acelp_core_dec_ivas_fx.c
+++ b/lib_dec/acelp_core_dec_ivas_fx.c
@@ -194,13 +194,6 @@ ivas_error acelp_core_dec_ivas_fx(
             }
 #endif
             ApplyFdCng_ivas_fx( NULL, 0, NULL, 0, NULL, NULL, NULL, st, 0, 0 );
-
-            IF( st->hFdCngDec->hFdCngCom->cngNoiseLevelExp < 0 )
-            {
-                Scale_sig32( st->hFdCngDec->hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, st->hFdCngDec->hFdCngCom->cngNoiseLevelExp );
-                st->hFdCngDec->hFdCngCom->cngNoiseLevelExp = 0;
-                move16();
-            }
         }
         ELSE
         {
@@ -698,26 +691,7 @@ ivas_error acelp_core_dec_ivas_fx(
                         move32();
                     }
 #endif
-                    Word16 new_sidNoiseEstExp = 31 - Q4;
-                    move16();
-                    Scale_sig32( st->hFdCngDec->hFdCngCom->sidNoiseEstLp, NPART, sub( st->hFdCngDec->hFdCngCom->sidNoiseEstExp, new_sidNoiseEstExp ) );
-                    Scale_sig32( st->hFdCngDec->hFdCngCom->sidNoiseEst, NPART, sub( st->hFdCngDec->hFdCngCom->sidNoiseEstExp, new_sidNoiseEstExp ) );
-                    st->hFdCngDec->hFdCngCom->sidNoiseEstExp = new_sidNoiseEstExp;
-                    move16();
-                    Word16 new_cngNoiseLevelExp = 31 - Q4;
-                    move16();
-                    Scale_sig32( st->hFdCngDec->hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, st->hFdCngDec->hFdCngCom->cngNoiseLevelExp - new_cngNoiseLevelExp );
-                    st->hFdCngDec->hFdCngCom->cngNoiseLevelExp = new_cngNoiseLevelExp;
-                    move16();
-
                     ApplyFdCng_ivas_fx( psyn_fx, st->Q_syn, NULL, 0, realBuffer_fx, imagBuffer_fx, NULL, st, 0, ( st->coder_type == AUDIO && !st->GSC_noisy_speech ) );
-
-                    IF( st->hFdCngDec->hFdCngCom->cngNoiseLevelExp < 0 )
-                    {
-                        Scale_sig32( st->hFdCngDec->hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, st->hFdCngDec->hFdCngCom->cngNoiseLevelExp );
-                        st->hFdCngDec->hFdCngCom->cngNoiseLevelExp = 0;
-                        move16();
-                    }
                 }
 
                 IF( !read_sid_info )
@@ -1547,30 +1521,9 @@ ivas_error acelp_core_dec_ivas_fx(
             IF( NE_16( st->element_mode, IVAS_CPE_TD ) && !st->cng_ism_flag )
             {
                 /*Noise estimate*/
-
-                Scale_sig32( st->hFdCngDec->hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, sub( st->hFdCngDec->hFdCngCom->cngNoiseLevelExp, Q27 ) );
-                st->hFdCngDec->hFdCngCom->cngNoiseLevelExp = 31 - Q4; // Q4
-                move16();
-
-                Scale_sig32( st->hFdCngDec->hFdCngCom->sidNoiseEst, NPART, sub( st->hFdCngDec->hFdCngCom->sidNoiseEstExp, Q27 ) );
-                Scale_sig32( st->hFdCngDec->hFdCngCom->sidNoiseEstLp, NPART, sub( st->hFdCngDec->hFdCngCom->sidNoiseEstExp, Q27 ) );
-                st->hFdCngDec->hFdCngCom->sidNoiseEstExp = 31 - Q4; // Q4
-                move16();
                 /*==========================================================*/
                 ApplyFdCng_ivas_fx( psyn_fx, st->Q_syn, NULL, 0, realBuffer_fx, imagBuffer_fx, NULL, st, 0, ( st->coder_type == AUDIO && !st->GSC_noisy_speech ) );
                 /*==========================================================*/
-                IF( st->hFdCngDec->partNoiseShape_exp < 0 )
-                {
-                    Scale_sig32( st->hFdCngDec->partNoiseShape, NPART, st->hFdCngDec->partNoiseShape_exp );
-                    st->hFdCngDec->partNoiseShape_exp = 0;
-                    move16();
-                }
-                IF( st->hFdCngDec->hFdCngCom->cngNoiseLevelExp < 0 )
-                {
-                    Scale_sig32( st->hFdCngDec->hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, st->hFdCngDec->hFdCngCom->cngNoiseLevelExp );
-                    st->hFdCngDec->hFdCngCom->cngNoiseLevelExp = 0;
-                    move16();
-                }
             }
 
             IF( !st->cna_dirac_flag )
@@ -1656,24 +1609,6 @@ ivas_error acelp_core_dec_ivas_fx(
                     IF( ( st->idchan == 0 ) && ( EQ_16( nchan_out, 2 ) || ( st->core_brate != FRAME_NO_DATA && NE_32( st->core_brate, SID_2k40 ) ) ) )
                     {
                         ApplyFdCng_ivas_fx( psyn_fx, st->Q_syn, NULL, 0, realBuffer_fx, imagBuffer_fx, NULL, st, 0, ( st->coder_type == AUDIO && !st->GSC_noisy_speech ) );
-                        IF( st->hFdCngDec->partNoiseShape_exp < 0 )
-                        {
-                            Scale_sig32( st->hFdCngDec->partNoiseShape, NPART, -st->hFdCngDec->partNoiseShape_exp );
-                            st->hFdCngDec->partNoiseShape_exp = 0;
-                            move16();
-                        }
-                        IF( st->hFdCngDec->partNoiseShape_exp < 0 )
-                        {
-                            Scale_sig32( st->hFdCngDec->partNoiseShape, NPART, st->hFdCngDec->partNoiseShape_exp );
-                            st->hFdCngDec->partNoiseShape_exp = 0;
-                            move16();
-                        }
-                        IF( st->hFdCngDec->hFdCngCom->cngNoiseLevelExp < 0 )
-                        {
-                            Scale_sig32( st->hFdCngDec->hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, st->hFdCngDec->hFdCngCom->cngNoiseLevelExp );
-                            st->hFdCngDec->hFdCngCom->cngNoiseLevelExp = 0;
-                            move16();
-                        }
                     }
                 }
             }
diff --git a/lib_dec/fd_cng_dec_fx.c b/lib_dec/fd_cng_dec_fx.c
index ae13e69c8cc42a9075b4cf7f9088b46f8f08f0fd..2dc687237f59983b56245c11bdd08cdb87278c42 100644
--- a/lib_dec/fd_cng_dec_fx.c
+++ b/lib_dec/fd_cng_dec_fx.c
@@ -1383,16 +1383,26 @@ Word16 ApplyFdCng_ivas_fx(
                     IF( NE_16( s2, -( WORD32_BITS - 1 ) ) )
                     {
                         s = sub( *cngNoiseLevel_exp, add( hFdCngDec->bandNoiseShape_exp, s2 ) );
+                        Word16 e_shift = 0;
+                        IF( s > 0 )
+                        {
+                            Word16 q_norm = L_norm_arr( &cngNoiseLevel[j], sub( FFTCLDFBLEN, j ) );
+                            IF( GT_16( s, q_norm ) )
+                            {
+                                scale_sig32( cngNoiseLevel, j, sub( q_norm, s ) );
+                                e_shift = sub( s, q_norm );
+                            }
+                        }
                         FOR( ; k < hFdCngCom->npart; k++ )
                         {
                             FOR( ; j <= hFdCngCom->part[k]; j++ )
                             {
-                                cngNoiseLevel[j] = L_shl( cngNoiseLevel[j], s );
+                                cngNoiseLevel[j] = L_shl( cngNoiseLevel[j], sub( s, e_shift ) );
                                 move32();
                             }
                         }
 
-                        *cngNoiseLevel_exp = add( hFdCngDec->bandNoiseShape_exp, s2 );
+                        *cngNoiseLevel_exp = add( add( hFdCngDec->bandNoiseShape_exp, s2 ), e_shift );
                         move16();
                     }
                 }
@@ -2410,14 +2420,16 @@ void perform_noise_estimation_dec_ivas_fx(
     Word32 temp, ftemp, delta, L_tmp;
     Word16 e_temp, wght, periodog_exp;
     Word32 enr, enr_tot, enr_tot0;
-    Word16 enr_ratio, alpha;
+    Word16 enr_e, enr_ratio, alpha;
     Word32 *msPeriodog;
     Word32 *msNoiseEst;
     Word32 *reIter;
     Word32 rescale_fac = 0;
     Word64 W_tmp;
     Word16 tmp_s, tmp_q, min_q = 31;
-    Word16 exp_flag = 0;
+    Word16 q_shift;
+    Word32 max_l;
+    Word16 norm_shift;
 #ifdef IVAS_CODE_CNG
     PMT( "lots of code related to IVAS needs to be done " )
 #endif
@@ -2639,62 +2651,47 @@ void perform_noise_estimation_dec_ivas_fx(
             enr_tot0 = L_add_sat( L_shr( sum32_fx( msNoiseEst, npart ), sub( hFdCngDec->msPeriodog_exp, hFdCngDec->msNoiseEst_exp ) ), 1 );
         }
 
+        /* update short-term periodogram on larger partitions */
+        maximum_32_fx( &msPeriodog[CNA_ACT_DN_LARGE_PARTITION], sub( npart, CNA_ACT_DN_LARGE_PARTITION ), &max_l );
+        q_shift = sub( hFdCngDec->hFdCngCom->periodog_exp, hFdCngDec->msPeriodog_ST_exp );
+        norm_shift = norm_l( max_l );
         test();
-        IF( !( NE_16( L_frame, last_L_frame ) || LE_32( last_core_brate, SID_2k40 ) ) )
+        IF( max_l && GT_16( q_shift, norm_shift ) )
         {
-            IF( GT_16( hFdCngDec->hFdCngCom->periodog_exp, hFdCngDec->msPeriodog_ST_exp ) )
-            {
-                exp_flag = 1;
-                move16();
-            }
-            ELSE
-            {
-                exp_flag = 0;
-                move16();
-            }
+            scale_sig32( hFdCngDec->msPeriodog_ST_fx, NPART_SHAPING, sub( norm_shift, q_shift ) );
+            hFdCngDec->msPeriodog_ST_exp = sub( hFdCngDec->msPeriodog_ST_exp, sub( norm_shift, q_shift ) );
+            move16();
+            q_shift = norm_shift;
+            move16();
         }
-
-        /* update short-term periodogram on larger partitions */
         FOR( p = CNA_ACT_DN_LARGE_PARTITION; p < npart; p++ )
         {
             test();
+            q_shift = sub( hFdCngDec->hFdCngCom->periodog_exp, hFdCngDec->msPeriodog_ST_exp );
             IF( NE_16( L_frame, last_L_frame ) || LE_32( last_core_brate, SID_2k40 ) )
             {
                 /* core Fs has changed or last frame was SID/NO_DATA -> re-initialize short-term periodogram */
-                hFdCngDec->msPeriodog_ST_fx[p] = msPeriodog[p];
+                hFdCngDec->msPeriodog_ST_fx[p] = L_shl( msPeriodog[p], q_shift );
                 move32();
-                hFdCngDec->msPeriodog_ST_exp = hFdCngDec->hFdCngCom->periodog_exp;
-                move16();
             }
             ELSE
             {
-                temp = msPeriodog[p];
-                move32();
-                IF( exp_flag )
-                {
-                    hFdCngDec->msPeriodog_ST_fx[p] = L_shr( hFdCngDec->msPeriodog_ST_fx[p], sub( hFdCngDec->hFdCngCom->periodog_exp, hFdCngDec->msPeriodog_ST_exp ) );
-                    move32();
-                }
-                ELSE
-                {
-                    temp = L_shr( temp, sub( hFdCngDec->msPeriodog_ST_exp, hFdCngDec->hFdCngCom->periodog_exp ) );
-                }
 #ifdef IVAS_ENH32_CADENCE_CHANGES
-                hFdCngDec->msPeriodog_ST_fx[p] = Madd_32_16( Mpy_32_16_1( hFdCngDec->msPeriodog_ST_fx[p], ST_PERIODOG_FACT_Q15 ), temp, sub( MAX_16, ST_PERIODOG_FACT_Q15 ) );
+                temp = L_shl( msPeriodog[p], q_shift );
+                hFdCngDec->msPeriodog_ST_fx[p] = Madd_32_16( Mpy_32_16_1( hFdCngDec->msPeriodog_ST_fx[p], ST_PERIODOG_FACT_Q15 ), temp, MAX_16 - ST_PERIODOG_FACT_Q15 );
 #else
                 hFdCngDec->msPeriodog_ST_fx[p] = L_add( Mpy_32_16_1( hFdCngDec->msPeriodog_ST_fx[p], ST_PERIODOG_FACT_Q15 ), Mpy_32_16_1( temp, sub( MAX_16, ST_PERIODOG_FACT_Q15 ) ) );
 #endif
                 move32();
             }
         }
-        test();
-        IF( !( NE_16( L_frame, last_L_frame ) || LE_32( last_core_brate, SID_2k40 ) ) )
+        maximum_32_fx( hFdCngDec->msPeriodog_ST_fx, NPART_SHAPING, &max_l );
+        IF( max_l )
         {
-            IF( exp_flag )
-            {
-                hFdCngDec->msPeriodog_ST_exp = hFdCngDec->hFdCngCom->periodog_exp;
-                move16();
-            }
+            q_shift = sub( norm_l( max_l ), 2 );
+            scale_sig32( hFdCngDec->msPeriodog_ST_fx, NPART_SHAPING, q_shift );
+            hFdCngDec->msPeriodog_ST_exp = sub( hFdCngDec->msPeriodog_ST_exp, q_shift );
+            move16();
         }
 
         /* core Fs has changed -> partitions have changed -> re-calculate long-term periodogram */
@@ -2755,30 +2752,35 @@ void perform_noise_estimation_dec_ivas_fx(
                 IF( NE_16( hFdCngDec->first_cna_noise_update_cnt, 0 ) )
                 {
                     alpha = Inv16( add( hFdCngDec->first_cna_noise_update_cnt, 1 ), &e );
-                    IF( LT_16( e, 0 ) )
+                    alpha = shl_sat( alpha, e ); // Q15
+                    maximum_32_fx( msPeriodog, npart, &max_l );
+                    q_shift = sub( hFdCngDec->hFdCngCom->periodog_exp, hFdCngDec->msNoiseEst_exp );
+                    norm_shift = norm_l( max_l );
+                    test();
+                    IF( max_l && GT_16( q_shift, norm_shift ) )
                     {
-                        alpha = shr( alpha, negate( e ) ); // Q15
+                        scale_sig32( msNoiseEst, NPART_SHAPING, sub( norm_shift, q_shift ) );
+                        hFdCngDec->msNoiseEst_exp = sub( hFdCngDec->msNoiseEst_exp, sub( norm_shift, q_shift ) );
+                        move16();
+                        q_shift = norm_shift;
+                        move16();
                     }
                     FOR( p = 0; p < npart; p++ )
                     {
-                        temp = msPeriodog[p];
-                        move32();
-                        temp = L_shr( temp, sub( hFdCngDec->msNoiseEst_exp, hFdCngDec->msPeriodog_exp ) );
+                        temp = L_shl( msPeriodog[p], q_shift );
 #ifdef IVAS_ENH32_CADENCE_CHANGES
-                        msNoiseEst[p] = Madd_32_16( Mpy_32_16_1( msNoiseEst[p], sub( shl_sat( 1, sub( 15, e ) ), alpha ) ), temp, alpha );
+                        msNoiseEst[p] = Madd_32_16( Mpy_32_16_1( msNoiseEst[p], sub( MAX_16, alpha ) ), temp, alpha );
 #else
-                        msNoiseEst[p] = L_add( Mpy_32_16_1( msNoiseEst[p], sub( shl_sat( 1, sub( 15, e ) ), alpha ) ), Mpy_32_16_1( temp, alpha ) );
+                        msNoiseEst[p] = L_add( Mpy_32_16_1( msNoiseEst[p], sub( MAX_16, alpha ) ), Mpy_32_16_1( temp, alpha ) );
 #endif
                         move32();
                     }
                 }
                 ELSE
                 {
-                    FOR( p = 0; p < npart; p++ )
-                    {
-                        msNoiseEst[p] = L_shr( msPeriodog[p], sub( hFdCngDec->msNoiseEst_exp, hFdCngDec->msPeriodog_exp ) );
-                        move32();
-                    }
+                    Copy32( msPeriodog, msNoiseEst, npart );
+                    scale_sig32( &msNoiseEst[npart], sub( NPART_SHAPING, npart ), sub( hFdCngDec->msNoiseEst_exp, hFdCngDec->msPeriodog_exp ) );
+                    hFdCngDec->msNoiseEst_exp = hFdCngDec->msPeriodog_exp;
                 }
 
                 /* check, if we reached the required number of first CNA noise update frames */
@@ -2863,7 +2865,7 @@ void perform_noise_estimation_dec_ivas_fx(
                     /* energy significantly decreases in one of the larger partitions during active frames -> downward update */
                     FOR( p = CNA_ACT_DN_LARGE_PARTITION; p < npart; p++ )
                     {
-                        L_tmp = L_shr( hFdCngDec->msPeriodog_ST_fx[p], sub( hFdCngDec->msNoiseEst_exp, hFdCngDec->msPeriodog_ST_exp ) );
+                        L_tmp = L_shr_sat( hFdCngDec->msPeriodog_ST_fx[p], sub( hFdCngDec->msNoiseEst_exp, hFdCngDec->msPeriodog_ST_exp ) );
                         IF( LT_32( L_tmp, msNoiseEst[p] ) )
                         {
 #ifdef IVAS_ENH32_CADENCE_CHANGES
@@ -2895,7 +2897,8 @@ void perform_noise_estimation_dec_ivas_fx(
                     move16();
                     enr = msPeriodog[p];
                     move32();
-                    temp = L_shr( enr, sub( hFdCngDec->msNoiseEst_exp, hFdCngDec->msPeriodog_exp ) );
+                    enr_e = hFdCngDec->msPeriodog_exp;
+                    move16();
                     alpha = 31130; // 0.95f in Q15
                     move16();
                     /* bandwidth increased -> do fast re-initilization  */
@@ -2908,16 +2911,29 @@ void perform_noise_estimation_dec_ivas_fx(
                             alpha = shr( alpha, negate( i_e ) ); // Q15
                         }
                     }
-                    ELSE IF( LT_32( temp, *ptr_per ) && EQ_16( part[p], 1 ) )
+                    ELSE IF( ( BASOP_Util_Cmp_Mant32Exp( enr, enr_e, *ptr_per, hFdCngDec->msNoiseEst_exp ) < 0 ) && EQ_16( part[p], 1 ) )
                     {
                         /* faster downward update for single-bin partitions */
                         alpha = 26214; // 0.8f in Q15
                         move16();
                     }
-                    ELSE IF( GT_32( temp, L_shl( ( *ptr_per ), 1 ) ) )
+                    ELSE IF( BASOP_Util_Cmp_Mant32Exp( enr, enr_e, *ptr_per, add( hFdCngDec->msNoiseEst_exp, 1 ) ) > 0 )
                     {
                         /* prevent abrupt upward updates */
-                        temp = L_shl( ( *ptr_per ), 1 );
+                        test();
+                        IF( ( norm_l( *ptr_per ) == 0 ) && *ptr_per )
+                        {
+                            enr = *ptr_per;
+                            scale_sig32( msNoiseEst, NPART_SHAPING, -1 );
+                            hFdCngDec->msNoiseEst_exp = add( hFdCngDec->msNoiseEst_exp, 1 );
+                            move16();
+                        }
+                        ELSE
+                        {
+                            enr = L_shl( *ptr_per, 1 );
+                        }
+                        enr_e = hFdCngDec->msNoiseEst_exp;
+                        move16();
                     }
 
                     /* IIR smoothing */
@@ -2938,9 +2954,27 @@ void perform_noise_estimation_dec_ivas_fx(
                         move32();
                     }
 #ifdef IVAS_ENH32_CADENCE_CHANGES
-                    *ptr_per = Madd_32_16( ( *ptr_per ), temp, sub( MAX_16, alpha ) );
+                    if ( enr )
+                    {
+                        q_shift = sub( enr_e, hFdCngDec->msNoiseEst_exp );
+                        norm_shift = norm_l( enr );
+                        if ( LE_16( q_shift, norm_shift ) )
+                        {
+                            enr = L_shl( enr, q_shift );
+                            move32();
+                        }
+                        else
+                        {
+                            enr_e = sub( enr_e, norm_shift );
+                            enr = L_shl( enr, norm_shift );
+                            scale_sig32( msNoiseEst, NPART_SHAPING, sub( norm_shift, q_shift ) );
+                            hFdCngDec->msNoiseEst_exp = sub( hFdCngDec->msNoiseEst_exp, sub( norm_shift, q_shift ) );
+                            move16();
+                        }
+                    }
+                    *ptr_per = Madd_32_16( ( *ptr_per ), enr, sub( MAX_16, alpha ) );
 #else
-                    *ptr_per = L_add( ( *ptr_per ), Mpy_32_16_1( temp, sub( MAX_16, alpha ) ) );
+                    *ptr_per = L_add( ( *ptr_per ), Mpy_32_16_1( enr, sub( MAX_16, alpha ) ) );
 #endif
                     ptr_per++;
                 }
@@ -2951,6 +2985,14 @@ void perform_noise_estimation_dec_ivas_fx(
                 }
             }
         }
+        maximum_32_fx( msNoiseEst, NPART_SHAPING, &max_l );
+        if ( max_l )
+        {
+            q_shift = sub( norm_l( max_l ), 2 );
+            scale_sig32( msNoiseEst, NPART_SHAPING, q_shift );
+            hFdCngDec->msNoiseEst_exp = sub( hFdCngDec->msNoiseEst_exp, q_shift );
+            move16();
+        }
 
         Copy32( msNoiseEst, hFdCngDec->msPsd_fx, npart );
         hFdCngDec->msPsd_exp_fft = hFdCngDec->msNoiseEst_exp;
diff --git a/lib_dec/ivas_core_dec.c b/lib_dec/ivas_core_dec.c
index 800e20f5b30173db199dedd9c34323c92b30ae37..2bfd615b0bb8ffef84285cb0d43404eb167a83f2 100644
--- a/lib_dec/ivas_core_dec.c
+++ b/lib_dec/ivas_core_dec.c
@@ -531,10 +531,6 @@ ivas_error ivas_core_dec_fx(
 
             IF( st->hFdCngDec != NULL )
             {
-                Scale_sig32( st->hFdCngDec->msNoiseEst, NPART_SHAPING, sub( st->hFdCngDec->msNoiseEst_exp, 27 ) );
-                st->hFdCngDec->msNoiseEst_exp = 27;
-                move16();
-
                 Scale_sig( st->hFdCngDec->hFdCngCom->A_cng, add( M, 1 ), sub( norm_s( sub( st->hFdCngDec->hFdCngCom->A_cng[0], 1 ) ), 3 ) );
             }
 
@@ -613,9 +609,6 @@ ivas_error ivas_core_dec_fx(
             /* TCX decoder */
             Scale_sig( st->hPFstat->mem_stp, L_SUBFR, -Qsyn_temp );
             Scale_sig( st->hPFstat->mem_pf_in, L_SUBFR, -Qsyn_temp );
-            Scale_sig32( st->hFdCngDec->msNoiseEst, NPART_SHAPING, sub( st->hFdCngDec->msNoiseEst_exp, 27 ) );
-            st->hFdCngDec->msNoiseEst_exp = 27;
-            move16();
             Scale_sig( st->hHQ_core->old_out_LB_fx, L_FRAME32k, -st->hHQ_core->Q_old_wtda_LB );
             Scale_sig( st->hHQ_core->old_out_fx, L_FRAME48k, -st->hHQ_core->Q_old_wtda );
 
@@ -822,10 +815,6 @@ ivas_error ivas_core_dec_fx(
             {
                 IF( NE_16( sts[n]->last_core_bfi, ACELP_CORE ) )
                 {
-                    Scale_sig32( sts[n]->hFdCngDec->hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, sub( sts[n]->hFdCngDec->hFdCngCom->cngNoiseLevelExp, 27 ) );
-                    sts[n]->hFdCngDec->hFdCngCom->cngNoiseLevelExp = 27;
-                    move16();
-
                     TonalMdctConceal_whiten_noise_shape_ivas_fx( sts[n], L_FRAME16k, ON_FIRST_GOOD_FRAME );
                 }
             }
diff --git a/lib_dec/ivas_stereo_cng_dec.c b/lib_dec/ivas_stereo_cng_dec.c
index 728709de509354eaaf7aa0b6d85db219e4aa9093..364b0316a25a48ef87d0d4266caa727fa57b8549 100644
--- a/lib_dec/ivas_stereo_cng_dec.c
+++ b/lib_dec/ivas_stereo_cng_dec.c
@@ -695,6 +695,7 @@ static void stereo_dft_generate_comfort_noise_fx(
     Word16 numSlots;
     Word16 scale, inv_scale, tmp_16;
     Word32 lp_noise;
+    Word16 lp_noise_e;
     Word32 tmp, enr;
     Word16 q_enr;
     Word32 shb_shape[L_FRAME16k];
@@ -704,7 +705,8 @@ static void stereo_dft_generate_comfort_noise_fx(
     Word32 cngNoiseLevel_upd[L_FRAME16k], cngNoiseLevel_hist[L_FRAME16k - 2];
     Word16 e_norm_temp[L_FRAME16k];
     Word32 *ptr_tmp, *ptr_cng;
-    Word32 E0, E1;
+    Word64 E0, E1;
+    Word16 E0_e, E1_e;
     Word16 b, q_cngNoiseLevel_upd, q_cngNoiseLevel;
     Word32 *pSideGain;
     Word16 gamma;
@@ -734,21 +736,22 @@ static void stereo_dft_generate_comfort_noise_fx(
     set_zero_fx( DFT[chan], STEREO_DFT_BUF_MAX );
     set32_fx( cngNoiseLevel_upd, 0, L_FRAME16k );
 
-    q_shift = s_min( getScaleFactor32( hFdCngCom->cngNoiseLevel, FFTCLDFBLEN ), sub( hFdCngCom->cngNoiseLevelExp, 27 ) );
-    scale_sig32( hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, q_shift );
-    hFdCngCom->cngNoiseLevelExp = sub( hFdCngCom->cngNoiseLevelExp, q_shift );
-    move16();
-
     enr = 0; /* Eliminates compiler warning. They are always set before they are used */
     move32();
     q_enr = 0;
     move16();
     E0 = 0;
-    move32();
+    move64();
+    E0_e = 0;
+    move16();
     E1 = 0;
-    move32();
+    move64();
+    E1_e = 0;
+    move16();
     lp_noise = 0;
     move32();
+    lp_noise_e = 0;
+    move16();
     q_shb_shape = 0;
     move16();
 
@@ -1032,10 +1035,10 @@ static void stereo_dft_generate_comfort_noise_fx(
         ptr_cng = cngNoiseLevel_hist;
         FOR( i = 0; i < shr( sub( st->last_L_frame, hFdCngCom->startBand ), 1 ); i++ )
         {
-            tmp = *( cngNoiseLevel_hist + shl( i, 1 ) );
+            tmp = L_shr( *( cngNoiseLevel_hist + shl( i, 1 ) ), 1 );
             move32();
-            tmp = L_add( tmp, *( cngNoiseLevel_hist + add( shl( i, 1 ), 1 ) ) );
-            *ptr_cng++ = L_shr( tmp, 1 );
+            tmp = L_add( tmp, L_shr( *( cngNoiseLevel_hist + add( shl( i, 1 ), 1 ) ), 1 ) );
+            *ptr_cng++ = tmp;
             move32();
         }
 
@@ -1048,14 +1051,21 @@ static void stereo_dft_generate_comfort_noise_fx(
             ptr_tmp = cngNoiseLevel_upd + hFdCngCom->startBand;
             FOR( i = 0; i < shr( sub( st->last_L_frame, hFdCngCom->startBand ), 1 ); i++ )
             {
-                E0 = L_add( E0, *ptr_cng++ );
-                E1 = L_add( E1, Mpy_32_32( ( *ptr_tmp ), ( *ptr_tmp ) ) );
+                E0 = W_add( E0, *ptr_cng++ );
+                E1 = W_mac_32_32( E1, ( *ptr_tmp ), ( *ptr_tmp ) );
                 ptr_tmp++;
             }
+            E0_e = W_norm( E0 );
+            E0 = W_shl( E0, E0_e );
+            E0_e = add( sub( st->hFdCngDec->bandNoiseShape_exp, E0_e ), 32 );
+            E1_e = W_norm( E1 );
+            E1 = W_shl( E0, E1_e );
+            E1_e = sub( 63, add( E1_e, add( shl( q_cngNoiseLevel_upd, 1 ), 1 ) ) );
 
-            tmp_16 = BASOP_Util_Divide3232_Scale( E0, E1, &q_div );
+            tmp_16 = BASOP_Util_Divide3232_Scale( W_extract_h( E0 ), W_extract_h( E1 ), &q_div );
+            q_div = add( q_div, sub( E0_e, E1_e ) );
             tmp_16 = Sqrt16( tmp_16, &q_div );
-            IF( LT_16( tmp_16, shr_sat( MAX_16, q_div ) ) )
+            IF( BASOP_Util_Cmp_Mant32Exp( tmp_16, add( 16, q_div ), MAX_32, 0 ) < 0 )
             {
                 tmp_16 = shl( tmp_16, q_div );
                 hStereoCng->xfade_length = sub( MAX_XFADE_FX, extract_l( L_shr( imult3216( MAX_XFADE_FX, tmp_16 ), Q15 ) ) );
@@ -1063,9 +1073,8 @@ static void stereo_dft_generate_comfort_noise_fx(
             }
             ELSE
             {
-                Word16 q_inv;
-                tmp_16 = Invert16( tmp_16, &q_inv );
-                tmp_16 = shl( tmp_16, add( q_inv, q_div ) );
+                tmp_16 = Inv16( tmp_16, &q_div );
+                tmp_16 = shl( tmp_16, q_div );
                 hStereoCng->xfade_length = sub( MAX_XFADE_FX, extract_l( L_shr( imult3216( MAX_XFADE_FX, tmp_16 ), Q15 ) ) );
                 move16();
             }
@@ -1221,6 +1230,8 @@ static void stereo_dft_generate_comfort_noise_fx(
         /* Expand cngNoiseLevel_flt from 0-159 to 0-318, compute noise level */
         lp_noise = 0;
         move32();
+        lp_noise_e = 0;
+        move16();
         ptr_level = hFdCngCom->cngNoiseLevel + sub( hFdCngCom->stopFFTbin, add( hFdCngCom->startBand, 1 ) );
         ptr_tmp = cngNoiseLevel_upd + sub( shr( sub( hFdCngCom->stopFFTbin, hFdCngCom->startBand ), 1 ), 1 );
 
@@ -1236,7 +1247,7 @@ static void stereo_dft_generate_comfort_noise_fx(
             ptr_tmp--;
             *ptr_level = *( ptr_level + 1 );
             move32();
-            lp_noise = L_add( lp_noise, L_shl( *ptr_level--, 1 ) );
+            lp_noise = BASOP_Util_Add_Mant32Exp( lp_noise, lp_noise_e, *ptr_level--, add( hFdCngCom->cngNoiseLevelExp, 1 ), &lp_noise_e );
         }
     }
     ELSE
@@ -1254,13 +1265,22 @@ static void stereo_dft_generate_comfort_noise_fx(
                 FOR( k = 0; k < sub( hFdCngCom->nFFTpart, 2 ); k++ )
                 {
                     factor = BASOP_Util_Divide3232_Scale_cadence( L_add( hFdCngCom->sidNoiseEstLp[k], DELTA_FX ), L_add( st->hFdCngDec->partNoiseShape[k], DELTA_FX ), &q_div );
-                    factor = s_min( add( hStereoDft->scale_fx, extract_l( Mpy_32_16_1( L_mult( sub( extract_h( factor ), hStereoDft->scale_fx ), hStereoCng->xfade_frame_counter ), ONE_BY_MAX_K ) ) ), extract_h( factor ) );
+                    q_div = add( q_div, sub( hFdCngCom->sidNoiseEstExp, st->hFdCngDec->partNoiseShape_exp ) );
+                    IF( q_div < 0 )
+                    {
+                        factor = L_shl( factor, q_div ); // Q31
+                        q_div = 0;
+                        move16();
+                    }
+                    factor = L_min( L_add( L_shl( hStereoDft->scale_fx, sub( 16, q_div ) ), W_extract_l( W_mult0_32_32( Mpy_32_16_1( L_sub( factor, L_shl( hStereoDft->scale_fx, sub( 16, q_div ) ) ), ONE_BY_MAX_K ), hStereoCng->xfade_frame_counter ) ) ), factor );
                     FOR( ; j <= hFdCngCom->part[k]; j++ )
                     {
-                        hFdCngCom->cngNoiseLevel[j] = Mpy_32_32( st->hFdCngDec->bandNoiseShape[j], factor );
+                        hFdCngCom->cngNoiseLevel[j] = L_shl( Mpy_32_32( st->hFdCngDec->bandNoiseShape[j], factor ), q_div );
                         move32();
                     }
                 }
+                hFdCngCom->cngNoiseLevelExp = st->hFdCngDec->bandNoiseShape_exp;
+                move16();
             }
         }
         scale = shr( output_frame, 1 );
@@ -1318,17 +1338,20 @@ static void stereo_dft_generate_comfort_noise_fx(
         /* Compute noise level */
         lp_noise = 0;
         move32();
+        lp_noise_e = 0;
+        move16();
         ptr_level = hFdCngCom->cngNoiseLevel;
         FOR( i = 0; i < sub( hFdCngCom->stopFFTbin, hFdCngCom->startBand ); i++ )
         {
-            lp_noise = L_add( lp_noise, *ptr_level++ );
+            // lp_noise = L_add( lp_noise, *ptr_level++ );
+            lp_noise = BASOP_Util_Add_Mant32Exp( lp_noise, lp_noise_e, *ptr_level++, hFdCngCom->cngNoiseLevelExp, &lp_noise_e );
         }
     }
 
     test();
     IF( EQ_16( hStereoCng->last_act_element_mode, IVAS_CPE_TD ) && ( chan > 0 ) )
     {
-        Word32 log_lp_noise = L_add( L_shl( hFdCngCom->cngNoiseLevelExp, Q25 ), BASOP_Util_Log2( L_add( lp_noise, DELTA_FX ) ) );
+        Word32 log_lp_noise = L_add( L_shl( lp_noise_e, Q25 ), BASOP_Util_Log2( L_add( lp_noise, DELTA_FX ) ) );
         // log10(x) is computed as log2(x) * log10(2)
         // log_lp_noise at this stage is in Q25. where as the structure value is in Q23
         // Hence the 16-bit constant log10(2) will be stored in Q13
@@ -1340,7 +1363,7 @@ static void stereo_dft_generate_comfort_noise_fx(
     {
         Word16 q_lp_noise = 0; // st->hFdCngDec->q_lp_noise; // to be populated appropriately.
         move16();
-        Word32 log_lp_noise = L_add( L_shl( hFdCngCom->cngNoiseLevelExp, Q25 ), BASOP_Util_Log2( L_add( lp_noise, DELTA_FX ) ) );
+        Word32 log_lp_noise = L_add( L_shl( lp_noise_e, Q25 ), BASOP_Util_Log2( L_add( lp_noise, DELTA_FX ) ) );
         // log10(x) is computed as log2(x) * log10(2)
         // log_lp_noise at this stage is in Q25. where as the structure value is in Q23
         // Hence the 16-bit constant log10(2) will be stored in Q13
@@ -1359,20 +1382,27 @@ static void stereo_dft_generate_comfort_noise_fx(
     test();
     IF( ( chan == 0 ) && LE_32( st->core_brate, SID_2k40 ) )
     {
-        Word32 max_smoothed_psd = 0;
-        move32();
-        (void) maximum_32_fx( &st->hFdCngDec->smoothed_psd_fx[hFdCngCom->startBand], sub( hFdCngCom->stopFFTbin, hFdCngCom->startBand ), &max_smoothed_psd );
         /* update smoothed periodogram used by stereo CNA in SID and NO_DATA frames from cngNoiseLevel_flt */
+        Word16 l_shift_val = sub( st->hFdCngDec->q_smoothed_psd, sub( Q31, hFdCngCom->cngNoiseLevelExp ) );
+        q_shift = L_norm_arr( st->hFdCngDec->smoothed_psd_fx, L_FRAME16k );
+        IF( GE_16( q_shift, negate( l_shift_val ) ) )
+        {
+            scale_sig32( st->hFdCngDec->smoothed_psd_fx, L_FRAME16k, negate( l_shift_val ) );
+            st->hFdCngDec->q_smoothed_psd = sub( Q31, hFdCngCom->cngNoiseLevelExp );
+            move16();
+        }
+        ELSE
+        {
+            scale_sig32( st->hFdCngDec->smoothed_psd_fx, L_FRAME16k, q_shift );
+            st->hFdCngDec->q_smoothed_psd = add( st->hFdCngDec->q_smoothed_psd, q_shift );
+            move16();
+            l_shift_val = add( q_shift, l_shift_val );
+            scale_sig32( hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, l_shift_val );
+            hFdCngCom->cngNoiseLevelExp = sub( hFdCngCom->cngNoiseLevelExp, l_shift_val );
+            move16();
+        }
         FOR( i = hFdCngCom->startBand; i < hFdCngCom->stopFFTbin; i++ )
         {
-            Word16 l_shift_val = sub( st->hFdCngDec->q_smoothed_psd, sub( Q31, hFdCngCom->cngNoiseLevelExp ) );
-
-            if ( max_smoothed_psd == 0 )
-            {
-                l_shift_val = 0;
-                move16();
-            }
-
             ftmp = hFdCngCom->cngNoiseLevel[sub( i, hFdCngCom->startBand )];
             move32();
             IF( !st->hFdCngDec->first_cna_noise_updated )
@@ -1385,14 +1415,14 @@ static void stereo_dft_generate_comfort_noise_fx(
             {
                 alpha = (Word16) ( 0x799A );
                 move16();
-                IF( ( st->hFdCngDec->smoothed_psd_fx[i] > 0 ) && GT_32( Mpy_32_16_1( ftmp, (Word16) 0x3333 ), L_shr_sat( st->hFdCngDec->smoothed_psd_fx[i], l_shift_val ) ) )
+                test();
+                IF( ( st->hFdCngDec->smoothed_psd_fx[i] > 0 ) && GT_32( Mpy_32_16_1( ftmp, (Word16) 0x3333 ), st->hFdCngDec->smoothed_psd_fx[i] ) )
                 {
                     /* prevent abrupt upward update steps */
                     ftmp = L_add( L_shl( st->hFdCngDec->smoothed_psd_fx[i], 1 ), L_shr( st->hFdCngDec->smoothed_psd_fx[i], 1 ) );
-                    l_shift_val = 0;
                     move16();
                 }
-                ELSE IF( LT_32( ftmp, L_shr( st->hFdCngDec->smoothed_psd_fx[i], l_shift_val ) ) )
+                ELSE IF( LT_32( ftmp, st->hFdCngDec->smoothed_psd_fx[i] ) )
                 {
                     /* faster downward updates */
                     alpha = (Word16) ( 0x599A );
@@ -1401,18 +1431,26 @@ static void stereo_dft_generate_comfort_noise_fx(
             }
 
             /* smoothing */
-            st->hFdCngDec->smoothed_psd_fx[i] = L_add( Mpy_32_16_1( st->hFdCngDec->smoothed_psd_fx[i], alpha ), L_shl( Mpy_32_16_1( ftmp, sub( MAX_16, alpha ) ), l_shift_val ) );
+            st->hFdCngDec->smoothed_psd_fx[i] = L_add( Mpy_32_16_1( st->hFdCngDec->smoothed_psd_fx[i], alpha ), Mpy_32_16_1( ftmp, sub( MAX_16, alpha ) ) );
             move32();
         }
 
         /* update msNoiseEst in SID and NO_DATA frames */
         bandcombinepow( &st->hFdCngDec->smoothed_psd_fx[hFdCngCom->startBand], sub( Q31, st->hFdCngDec->q_smoothed_psd ), sub( hFdCngCom->stopFFTbin, hFdCngCom->startBand ), st->hFdCngDec->part_shaping, st->hFdCngDec->nFFTpart_shaping, st->hFdCngDec->psize_inv_shaping, st->hFdCngDec->msNoiseEst, &st->hFdCngDec->msNoiseEst_exp );
-        Scale_sig32( st->hFdCngDec->msNoiseEst, NPART_SHAPING, sub( st->hFdCngDec->msNoiseEst_exp, 27 ) );
-        st->hFdCngDec->msNoiseEst_exp = 27;
-        move16();
+
+        Word32 max_l;
+        maximum_32_fx( st->hFdCngDec->msNoiseEst, NPART_SHAPING, &max_l );
+        IF( max_l )
+        {
+            q_shift = sub( norm_l( max_l ), 2 );
+            scale_sig32( st->hFdCngDec->msNoiseEst, NPART_SHAPING, q_shift );
+            st->hFdCngDec->msNoiseEst_exp = sub( st->hFdCngDec->msNoiseEst_exp, q_shift );
+            move16();
+        }
         st->hFdCngDec->first_cna_noise_updated = 1;
         move16();
         Copy32( st->hFdCngDec->msNoiseEst, st->hFdCngDec->msPeriodog_ST_fx, st->hFdCngDec->nFFTpart_shaping );
+        st->hFdCngDec->msPeriodog_ST_exp = st->hFdCngDec->msNoiseEst_exp;
         st->hFdCngDec->ms_last_inactive_bwidth = st->bwidth;
         move16();
     }
diff --git a/lib_dec/ivas_stereo_mdct_core_dec_fx.c b/lib_dec/ivas_stereo_mdct_core_dec_fx.c
index 7323d051324499f674af7eaebcb911f85fb9b1a7..7eef8c14a5c8888c7a464c818212e4aca294839a 100644
--- a/lib_dec/ivas_stereo_mdct_core_dec_fx.c
+++ b/lib_dec/ivas_stereo_mdct_core_dec_fx.c
@@ -1053,17 +1053,6 @@ static void run_min_stats_fx(
         test();
         IF( will_estimate_noise_on_channel[0] || will_estimate_noise_on_channel[1] || st->bfi )
         {
-            // for ( int p = 0; p < FFTCLDFBLEN; p++ )
-            {
-                // st->hFdCngDec->hFdCngCom->cngNoiseLevel[p] = L_shr ( st->hFdCngDec->hFdCngCom->cngNoiseLevel[p], sub( 28, st->hFdCngDec->hFdCngCom->cngNoiseLevelExp ) );
-            }
-            Scale_sig32( st->hFdCngDec->hFdCngCom->cngNoiseLevel, FFTCLDFBLEN, sub( st->hFdCngDec->hFdCngCom->cngNoiseLevelExp, 28 ) );
-            st->hFdCngDec->hFdCngCom->cngNoiseLevelExp = 31 - Q3; // Q3
-            Scale_sig32( st->hFdCngDec->msNoiseEst, NPART_SHAPING, sub( st->hFdCngDec->msNoiseEst_exp, 27 ) );
-            st->hFdCngDec->msNoiseEst_exp = 27;
-            // Scale_sig32(power_spec, L_FRAME16k, sub(power_spec_e, 31));
-            // power_spec_e = 31;
-            /*=================================================*/
             Word32 *arr_tmp;
             IF( st->bfi )
             {