diff --git a/lib_com/bitstream_fx.c b/lib_com/bitstream_fx.c
index b1c7a2efd07b91b3507671caf6a2b54ed18c92af..d2f3a61f6e6acba27e341a8037e60605126b1333 100644
--- a/lib_com/bitstream_fx.c
+++ b/lib_com/bitstream_fx.c
@@ -5235,7 +5235,7 @@ void evs_dec_previewFrame(
     return;
 }
 
-
+#ifndef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
 void dtx_read_padding_bits_fx(
     DEC_CORE_HANDLE st,
     const Word16 num_bits )
@@ -5253,3 +5253,4 @@ void dtx_read_padding_bits_fx(
 
     return;
 }
+#endif
diff --git a/lib_com/fd_cng_com_fx.c b/lib_com/fd_cng_com_fx.c
index 47e3df91ea423c8419b251649ef145603c7f901a..c8f0c31ac302487225d1f72345932585afb59c7e 100644
--- a/lib_com/fd_cng_com_fx.c
+++ b/lib_com/fd_cng_com_fx.c
@@ -2,6 +2,7 @@
     EVS Codec 3GPP TS26.452 Aug 12, 2021. Version 16.3.0
   ====================================================================================*/
 
+#include "ivas_cnst.h"
 #include <assert.h>
 #include <stdint.h>
 #include "options.h"
@@ -161,8 +162,12 @@ void ivas_initFdCngCom_fx( HANDLE_FD_CNG_COM hFdCngCom, Word16 scale )
     hFdCngCom->exp_cldfb_periodog = 0;
     move16();
 
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    set16_fx( hFdCngCom->coherence_fx, 16384 /* 0.5 in Q15 */, MDCT_ST_DTX_NUM_COHERENCE_BANDS );
+#else
     hFdCngCom->coherence_fx = 16384; /* 0.5 in Q15 */
     move16();
+#endif
 
     set32_fx( hFdCngCom->olapBufferSynth_fx, 0, FFTLEN );
     set32_fx( hFdCngCom->olapBufferSynth2_fx, 0, FFTLEN );
diff --git a/lib_com/ivas_cnst.h b/lib_com/ivas_cnst.h
index 41ffda19f3e461c6c90339092008762fc8dff3c9..c445d0299fa3acf3d7256648074877f853ad9c96 100644
--- a/lib_com/ivas_cnst.h
+++ b/lib_com/ivas_cnst.h
@@ -889,6 +889,11 @@ enum fea_names
 #define MDCT_ST_PLC_FADEOUT_TO_ZERO_LEN         20
 #define MDCT_ST_PLC_FADEOUT_DELAY_4_LSP_FADE    3
 
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+#define MDCT_ST_DTX_NUM_COHERENCE_BANDS         5
+#define MDCT_ST_DTX_FIRST_BAND_OFFSET           2
+#endif
+
 typedef enum {
     NOISE_GEN_MODE_UNDEF = -1,
     EQUAL_CORES = 0,
diff --git a/lib_com/ivas_prot_fx.h b/lib_com/ivas_prot_fx.h
index a01dedfbab4b4c97d98a09940b9fbb47eec1291f..ca39a3138bba37476a01f35d7fad695b1bcf9b62 100644
--- a/lib_com/ivas_prot_fx.h
+++ b/lib_com/ivas_prot_fx.h
@@ -1506,11 +1506,13 @@ ivas_error ivas_dirac_config_fx(
     void *st_ivas,                                              /* i/o: IVAS encoder/decoder state structure    */
     const Word16 enc_dec                                        /* i  : encoder or decoder flag                 */
 );
+#ifndef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
 
 void dtx_read_padding_bits_fx(
     DEC_CORE_HANDLE st,
     const Word16 num_bits 
 );
+#endif
 
 void FdCngEncodeMDCTStereoSID_fx(
     CPE_ENC_HANDLE hCPE                                         /* i/o: CPE encoder state structure             */
diff --git a/lib_com/ivas_rom_com.h b/lib_com/ivas_rom_com.h
index 44bc336d8abd7168bdfba669944e04bc8b1b2469..9773d0715db6cd47bb27636649ea460ce60daf37 100644
--- a/lib_com/ivas_rom_com.h
+++ b/lib_com/ivas_rom_com.h
@@ -133,6 +133,12 @@ extern const SpectrumWarping sw32000Hz[]; /* PsychLPC */
 
 extern const MDCTStereoBands_config mdctStereoBands_32000_640[];
 
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+extern const Word16 mdct_stereo_dtx_coherence_bandlengths[MDCT_ST_DTX_NUM_COHERENCE_BANDS];
+extern const Word16 get_next_index_4_by_15[16];
+#endif
+
+
 /*----------------------------------------------------------------------------------*
  * Stereo DTX ROM tables
  *----------------------------------------------------------------------------------*/
diff --git a/lib_com/ivas_rom_com_fx.c b/lib_com/ivas_rom_com_fx.c
index bd0dba245c6b67aae7b771c0cc9f69e2af5aaa32..dd99410ace5508d25b478f98e1b5a84e1af30823 100644
--- a/lib_com/ivas_rom_com_fx.c
+++ b/lib_com/ivas_rom_com_fx.c
@@ -546,6 +546,16 @@ const MDCTStereoBands_config mdctStereoBands_32000_640[] =
     {33, 29, 26, 18}/*number of bands for frame lengths 480, 320, 256, 160 respectively*/
 }};
 
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+const Word16 mdct_stereo_dtx_coherence_bandlengths[MDCT_ST_DTX_NUM_COHERENCE_BANDS] = {
+    6, /* 8 - MDCT_ST_DTX_FIRST_BAND_OFFSET */ 8, 16, 16, 80
+};
+/* dequantization table for coherence */
+const Word16 get_next_index_4_by_15[16] = {
+    0, 2184, 4369, 6553, 8738, 10922, 13107, 15291, 17476, 19660, 21845, 24029, 26214, 28398, 30583, 32767
+};
+#endif
+
 const Word16 dft_cng_coh_u2i[9] = { 4, 5, 3, 6, 2, 7, 1, 8, 0 }; /* Coherence unary codeword -> residual codeword conversion table */
 
 const Word16 dft_cng_coh_i2u[9] = { 8, 6, 4, 2, 0, 1, 3, 5, 7 }; /* Coherence residual codeword -> unary codeword conversion table */
diff --git a/lib_com/options.h b/lib_com/options.h
index 8171bdec930d790d42d6918da7c559b591170fed..2b5fe5729be45e2792a16589add08d1176b07490 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -132,6 +132,7 @@
 #define FIX_1383_HEAD_TRACK_SANITIZER                   /* Nok: issue 1383: Fix head tracking struc values reading in renderer */
 #define FIX_1330_JBM_MEMORY                             /* VA: issue 1330: memory savings in the JBM decoder */
 #define FIX_1411_IGF_CRASH_BW_SWITCHING                 /* FhG: Fix for issue 1411: fixes crash that can happen for IGF with BW switching and DTX*/
+#define NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG       /* FhG: Fix MDCT-Stereo comfort noise for certain noise types */
 
 // object-editing feature porting
 #define TMP_FIX_SPLIT_REND                              // temporary fix to split-rendering (it follows the later state of the framework but it is needed now because of current test-conditions)
diff --git a/lib_com/stat_com.h b/lib_com/stat_com.h
index 7b5c9fd104ab5458a2676b909691b5a492bff1ac..5309e7ad777915352c43affb12246db259cdf68a 100644
--- a/lib_com/stat_com.h
+++ b/lib_com/stat_com.h
@@ -38,6 +38,7 @@
 #ifndef STAT_COM_H
 #define STAT_COM_H
 
+#include "ivas_cnst.h"
 #include <stdint.h>
 #include "options.h"
 #include "typedef.h"
@@ -443,8 +444,12 @@ typedef struct
 
     Word16 flag_noisy_speech;
     Word16 likelihood_noisy_speech; /* Q15 */
-    Word16 coherence_fx;            /* inter-channel coherence of noise Q15 */
-    Word16 no_side_flag;            /* indicates whether the side noise shape should be zeroed-out or not */
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    Word16 coherence_fx[MDCT_ST_DTX_NUM_COHERENCE_BANDS]; /* inter-channel coherence of noise Q15 */
+#else
+    Word16 coherence_fx; /* inter-channel coherence of noise Q15 */
+#endif
+    Word16 no_side_flag; /* indicates whether the side noise shape should be zeroed-out or not */
 
 } FD_CNG_COM, *HANDLE_FD_CNG_COM;
 
diff --git a/lib_dec/fd_cng_dec_fx.c b/lib_dec/fd_cng_dec_fx.c
index d8805c4f268703c5b33ae3d35f456b6e61aa3a6a..756a39e9b1d8b54f76c911ecaafeab3d8efaa845 100644
--- a/lib_dec/fd_cng_dec_fx.c
+++ b/lib_dec/fd_cng_dec_fx.c
@@ -3,6 +3,13 @@
   ====================================================================================*/
 
 
+#include "basop32.h"
+#include "cnst.h"
+#include "enh1632.h"
+#include "ivas_cnst.h"
+#include "ivas_rom_com.h"
+#include "move.h"
+#include "wmc_auto.h"
 #include <assert.h>
 #include "typedef.h"
 #include <stdint.h>
@@ -2924,12 +2931,20 @@ void generate_comfort_noise_dec_ivas_fx(
 
     temp = 0;
     move16();
-    c1 = Sqrt16( hFdCngCom->coherence_fx, &temp ); /*Q15 - temp*/
-    c1 = shl( c1, temp );                          /*Q15*/
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    c1 = Sqrt16( hFdCngCom->coherence_fx[0], &temp ); /*Q15 - temp*/
+#else
+    c1 = Sqrt16( hFdCngCom->coherence_fx, &temp );                /*Q15 - temp*/
+#endif
+    c1 = shl( c1, temp ); /*Q15*/
     temp = 0;
     move16();
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    c2 = Sqrt16( sub( MAX_16, hFdCngCom->coherence_fx[0] ), &temp ); /*Q15 - temp*/
+#else
     c2 = Sqrt16( sub( MAX_16, hFdCngCom->coherence_fx ), &temp ); /*Q15 - temp*/
-    c2 = shl( c2, temp );                                         /*Q15*/
+#endif
+    c2 = shl( c2, temp ); /*Q15*/
 
     temp = getScaleFactor32( fftBuffer, FFTLEN );
     scale_sig32( fftBuffer, FFTLEN, temp ); /*Q31 - hFdCngCom->fftBuffer_exp + temp*/
@@ -2956,7 +2971,12 @@ void generate_comfort_noise_dec_ivas_fx(
     {
         test();
         test();
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+        test();
+        IF( ( EQ_16( st->element_mode, IVAS_CPE_MDCT && NE_16( nchan_out, 1 ) ) ) || ( EQ_16( st->element_mode, IVAS_SCE ) && st->cng_ism_flag ) )
+#else
         IF( EQ_16( st->element_mode, IVAS_CPE_MDCT ) || ( EQ_16( st->element_mode, IVAS_SCE ) && st->cng_ism_flag ) )
+#endif
         {
             rand_gauss_fx( &tmp1, seed, Q15 );
             rand_gauss_fx( &tmp2, seed2, Q15 );
@@ -2992,6 +3012,144 @@ void generate_comfort_noise_dec_ivas_fx(
     }
 
     ptr_i = ptr_r + 1; /*Q31 - fftBuffer_exp*/
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    test();
+    IF( EQ_16( st->element_mode, IVAS_CPE_MDCT ) && NE_16( nchan_out, 1 ) )
+    {
+        Word16 band_len_accu, b;
+
+        band_len_accu = 0;
+        move16();
+        i = 0;
+        move16();
+
+        FOR( b = 0; b < MDCT_ST_DTX_NUM_COHERENCE_BANDS; b++ )
+        {
+            band_len_accu = add( band_len_accu, mdct_stereo_dtx_coherence_bandlengths[b] );
+
+            /* First band needs to be shortened. The offset from encoder-side estimation is already in, so add it back here */
+            IF( EQ_16( b, 0 ) )
+            {
+                band_len_accu = add( band_len_accu, sub( MDCT_ST_DTX_FIRST_BAND_OFFSET, hFdCngCom->startBand ) );
+            }
+
+            /*
+             * for last band, we need to keep going until the end of the fft section - if there is still any
+             * this way, the coherence value of the last band is used for eveyrthing above as well
+             */
+            IF( EQ_16( b, sub( MDCT_ST_DTX_NUM_COHERENCE_BANDS, 1 ) ) )
+            {
+                band_len_accu = s_max( band_len_accu, sub( hFdCngCom->stopFFTbin, hFdCngCom->startBand ) );
+            }
+
+            /* mixing values for coherence is now frequency-dependent */
+            temp = 0;
+            move16();
+            c1 = Sqrt16( hFdCngCom->coherence_fx[b], &temp ); /*Q15 - temp*/
+            c1 = shl( c1, temp );                             /*Q15*/
+            temp = 0;
+            move16();
+            c2 = Sqrt16( sub( MAX_16, hFdCngCom->coherence_fx[b] ), &temp ); /*Q15 - temp*/
+            c2 = shl( c2, temp );                                            /*Q15*/
+
+            FOR( ; i < band_len_accu; i++ )
+            {
+                sqrtNoiseLevel_exp = sub( cngNoiseLevel_exp, 1 );
+                sqrtNoiseLevel = Sqrt32( *ptr_level, &sqrtNoiseLevel_exp ); /*Q31 - sqrtNoiseLevel_exp*/
+
+                /* Real part in FFT bins */
+                rand_gauss_fx( &tmp1, seed, Q15 );
+                rand_gauss_fx( &tmp2, seed2, Q15 );
+                *ptr_r = L_add( Mpy_32_16_1( tmp1, c1 ), Mpy_32_16_1( tmp2, c2 ) ); /*Q15*/
+                move32();
+                fftBuffer_temp_exp[idx] = Q16;
+                move16();
+                ( *ptr_r ) = Mpy_32_32( ( *ptr_r ), sqrtNoiseLevel ); /*Q15 - sqrtNoiseLevel_exp*/
+                move32();
+                fftBuffer_temp_exp[idx] = add( fftBuffer_temp_exp[idx], sqrtNoiseLevel_exp );
+                move16();
+                idx = add( idx, 1 );
+
+                /* Imaginary part in FFT bins */
+                rand_gauss_fx( &tmp1, seed, Q15 );                                  /*Q15*/
+                rand_gauss_fx( &tmp2, seed2, Q15 );                                 /*Q15*/
+                *ptr_i = L_add( Mpy_32_16_1( tmp1, c1 ), Mpy_32_16_1( tmp2, c2 ) ); /*Q15*/
+                move32();
+                fftBuffer_temp_exp[idx] = Q16;
+                move16();
+                ( *ptr_i ) = Mpy_32_32( ( *ptr_i ), sqrtNoiseLevel ); /*Q15 - sqrtNoiseLevel_exp*/
+                move32();
+                fftBuffer_temp_exp[idx] = add( fftBuffer_temp_exp[idx], sqrtNoiseLevel_exp );
+                move16();
+                idx = add( idx, 1 );
+
+                /* advance all pointers together here */
+                ptr_r += 2;
+                ptr_i += 2;
+                ptr_level++;
+            }
+        }
+    }
+    ELSE
+    {
+        FOR( ; ptr_level < cngNoiseLevel + sub( hFdCngCom->stopFFTbin, hFdCngCom->startBand ); ptr_level++ )
+        {
+            /* Real part in FFT bins */
+            test();
+            IF( EQ_16( st->element_mode, IVAS_SCE ) && st->cng_ism_flag )
+            {
+                rand_gauss_fx( &tmp1, seed, Q15 );                                  /*Q15*/
+                rand_gauss_fx( &tmp2, seed2, Q15 );                                 /*Q15*/
+                *ptr_r = L_add( Mpy_32_16_1( tmp1, c1 ), Mpy_32_16_1( tmp2, c2 ) ); /*Q15*/
+                move32();
+                fftBuffer_temp_exp[idx] = Q16;
+                move16();
+            }
+            ELSE
+            {
+                rand_gauss_fx( ptr_r, seed, Q15 ); /*Q15*/
+                fftBuffer_temp_exp[idx] = Q16;
+                move16();
+            }
+
+            sqrtNoiseLevel_exp = sub( cngNoiseLevel_exp, 1 );
+            sqrtNoiseLevel = Sqrt32( *ptr_level, &sqrtNoiseLevel_exp ); /*Q31 - sqrtNoiseLevel_exp*/
+            ( *ptr_r ) = Mpy_32_32( ( *ptr_r ), sqrtNoiseLevel );       /*Q15 - sqrtNoiseLevel_exp*/
+            move32();
+            fftBuffer_temp_exp[idx] = add( fftBuffer_temp_exp[idx], sqrtNoiseLevel_exp );
+            move16();
+            idx = add( idx, 1 );
+            ptr_r += 2;
+
+            /* Imaginary part in FFT bins */
+            test();
+            IF( EQ_16( st->element_mode, IVAS_SCE ) && st->cng_ism_flag )
+            {
+                rand_gauss_fx( &tmp1, seed, Q15 );                                  /*Q15*/
+                rand_gauss_fx( &tmp2, seed2, Q15 );                                 /*Q15*/
+                *ptr_i = L_add( Mpy_32_16_1( tmp1, c1 ), Mpy_32_16_1( tmp2, c2 ) ); /*Q15*/
+                move32();
+                fftBuffer_temp_exp[idx] = Q16;
+                move16();
+            }
+            ELSE
+            {
+                rand_gauss_fx( ptr_i, seed, Q15 ); /*Q15*/
+                fftBuffer_temp_exp[idx] = Q16;
+                move16();
+            }
+            sqrtNoiseLevel_exp = sub( cngNoiseLevel_exp, 1 );
+            sqrtNoiseLevel = Sqrt32( *ptr_level, &sqrtNoiseLevel_exp ); /*Q31 - sqrtNoiseLevel_exp*/
+            ( *ptr_i ) = Mpy_32_32( ( *ptr_i ), sqrtNoiseLevel );       /*Q15 - sqrtNoiseLevel_exp*/
+            move32();
+            fftBuffer_temp_exp[idx] = add( fftBuffer_temp_exp[idx], sqrtNoiseLevel_exp );
+            move16();
+            idx = add( idx, 1 );
+            ptr_i += 2;
+        }
+    }
+
+#else
     FOR( ; ptr_level < cngNoiseLevel + sub( hFdCngCom->stopFFTbin, hFdCngCom->startBand ); ptr_level++ )
     {
         /* Real part in FFT bins */
@@ -3049,6 +3207,7 @@ void generate_comfort_noise_dec_ivas_fx(
         idx = add( idx, 1 );
         ptr_i += 2;
     }
+#endif
 
     /* Remaining FFT bins are set to zero */
     set32_fx( fftBuffer + shl( hFdCngCom->stopFFTbin, 1 ), 0, sub( hFdCngCom->fftlen, shl( hFdCngCom->stopFFTbin, 1 ) ) );
@@ -3159,6 +3318,13 @@ void generate_comfort_noise_dec_ivas_fx(
     /* Generate Gaussian random noise in real and imaginary parts of the CLDFB bands
       Amplitudes are adjusted to the estimated noise level cngNoiseLevel_flt in each band */
 
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    /*
+     * Note: for the stereo DTX noise mixing, c1 and c2 at this point are set to the value calculated for the last band
+     *       as all the coherence bands are in the FFT region, we do not need the special handling here
+     */
+#endif
+
     test();
     IF( bufferReal != NULL && ( LT_16( hFdCngCom->numCoreBands, hFdCngCom->regularStopBand ) ) )
     {
@@ -3174,7 +3340,12 @@ void generate_comfort_noise_dec_ivas_fx(
             FOR( i = 0; i < hFdCngCom->numSlots; i++ )
             {
                 /* Real part in CLDFB band */
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+                test();
+                IF( ( EQ_16( st->element_mode, IVAS_CPE_MDCT ) && NE_16( nchan_out, 1 ) ) || ( EQ_16( st->element_mode, IVAS_SCE ) && st->cng_ism_flag ) )
+#else
                 IF( EQ_16( st->element_mode, IVAS_CPE_MDCT ) || ( EQ_16( st->element_mode, IVAS_SCE ) && st->cng_ism_flag ) )
+#endif
                 {
                     rand_gauss_fx( &tmp1, seed, Q15 );                                            /*Q15*/
                     rand_gauss_fx( &tmp2, seed2, Q15 );                                           /*Q15*/
@@ -3197,7 +3368,12 @@ void generate_comfort_noise_dec_ivas_fx(
                 move16();
 
                 /* Imaginary part in CLDFB band */
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+                test();
+                IF( ( EQ_16( st->element_mode, IVAS_CPE_MDCT ) && NE_16( nchan_out, 1 ) ) || ( EQ_16( st->element_mode, IVAS_SCE ) && st->cng_ism_flag ) )
+#else
                 IF( EQ_16( st->element_mode, IVAS_CPE_MDCT ) || ( EQ_16( st->element_mode, IVAS_SCE ) && st->cng_ism_flag ) )
+#endif
                 {
                     rand_gauss_fx( &tmp1, seed, Q15 );                                            /*Q15*/
                     rand_gauss_fx( &tmp2, seed2, Q15 );                                           /*Q15*/
@@ -3544,13 +3720,21 @@ void generate_comfort_noise_dec_hf_ivas_fx(
         s = 0;
         move16();
 
-        c1 = Sqrt16( hFdCngCom->coherence_fx, &s ); /*Q15 - s*/
-        c1 = shl( c1, s );                          // Q15
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+        c1 = Sqrt16( hFdCngCom->coherence_fx[sub( MDCT_ST_DTX_NUM_COHERENCE_BANDS, 1 )], &s ); /*Q15 - s*/
+#else
+        c1 = Sqrt16( hFdCngCom->coherence_fx, &s );                /*Q15 - s*/
+#endif
+        c1 = shl( c1, s ); // Q15
 
         s = 0;
         move16();
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+        c2 = Sqrt16( sub( MAX16B, hFdCngCom->coherence_fx[sub( MDCT_ST_DTX_NUM_COHERENCE_BANDS, 1 )] ), &s ); /*Q15 - s*/
+#else
         c2 = Sqrt16( sub( MAX16B, hFdCngCom->coherence_fx ), &s ); /*Q15 - s*/
-        c2 = shl( c2, s );                                         // Q15
+#endif
+        c2 = shl( c2, s ); // Q15
     }
 
     sn = 0;
@@ -5222,7 +5406,22 @@ void FdCngDecodeMDCTStereoSID_fx(
         Scale_sig32( ms_ptr_fx[ch], N, shift ); // Q20
     }
 
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    tmp32 = sts[1]->total_brate;
+    sts[1]->total_brate = L_add( sts[1]->total_brate, 800 /* 16 * FRAMES_PER_SEC */ );
+    /* read the four additional coherence values */
+    FOR( Word16 b = 1; b < MDCT_ST_DTX_NUM_COHERENCE_BANDS; b++ )
+    {
+        UWord16 idx;
+
+        idx = get_next_indice_fx( sts[1], 4 );
+        sts[0]->hFdCngDec->hFdCngCom->coherence_fx[b] = get_next_index_4_by_15[idx];
+        sts[1]->hFdCngDec->hFdCngCom->coherence_fx[b] = sts[0]->hFdCngDec->hFdCngCom->coherence_fx[b];
+    }
+    sts[1]->total_brate = tmp32;
+#else
     dtx_read_padding_bits_fx( sts[1], mult( sub( IVAS_SID_5k2, 4400 ), ONE_BY_FRAMES_PER_SEC_Q15 ) );
+#endif
 
     IF( sts[0]->hFdCngDec->hFdCngCom->no_side_flag )
     {
@@ -5407,10 +5606,21 @@ void FdCngDecodeDiracMDCTStereoSID_fx(
 
         lpc_from_spectrum( hFdCngCom, hFdCngCom->startBand, hFdCngCom->stopFFTbin, sts[ch]->preemph_fac );
     }
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    FOR( i = 0; i < MDCT_ST_DTX_NUM_COHERENCE_BANDS; i++ )
+    {
+        sts[0]->hFdCngDec->hFdCngCom->coherence_fx[i] = 0;
+        move16();
+        sts[1]->hFdCngDec->hFdCngCom->coherence_fx[i] = 0;
+        move16();
+    }
+
+#else
     sts[0]->hFdCngDec->hFdCngCom->coherence_fx = 0;
     move16();
     sts[1]->hFdCngDec->hFdCngCom->coherence_fx = 0;
     move16();
+#endif
 
     IF( EQ_16( hCPE->nchan_out, 1 ) )
     {
diff --git a/lib_dec/ivas_decision_matrix_dec_fx.c b/lib_dec/ivas_decision_matrix_dec_fx.c
index 717bb3b93512bdd8818088c6a585e9a2376d71b6..3eac102a3dc4106b994df9b258ab6eb37d4a4f25 100644
--- a/lib_dec/ivas_decision_matrix_dec_fx.c
+++ b/lib_dec/ivas_decision_matrix_dec_fx.c
@@ -33,7 +33,7 @@
 #include <stdint.h>
 #include "options.h"
 #include "stat_dec.h"
-#include "rom_com.h"
+#include "ivas_rom_com.h"
 #include "prot_fx.h"
 #include "ivas_cnst.h"
 #include "wmc_auto.h"
@@ -46,9 +46,11 @@
  * Read ACELP signaling bits from the bitstream
  * Set extension layers
  *-----------------------------------------------------------------*/
+#ifndef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
 static Word16 get_next_index_4_by_15[16] = {
     0, 2184, 4369, 6553, 8738, 10922, 13107, 15291, 17476, 19660, 21845, 24029, 26214, 28398, 30583, 32767
 };
+#endif
 void ivas_decision_matrix_dec_fx(
     Decoder_State *st,           /* i/o: decoder state structure             */
     Word16 *sharpFlag,           /* o  : formant sharpening flag             */
@@ -129,10 +131,13 @@ void ivas_decision_matrix_dec_fx(
             /* read channel coherence */
             Word16 index;
             index = get_next_indice_fx( st, 4 );
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+            st->hFdCngDec->hFdCngCom->coherence_fx[0] = get_next_index_4_by_15[index];
+#else
             st->hFdCngDec->hFdCngCom->coherence_fx = get_next_index_4_by_15[index];
+#endif
             move16();
 
-
             /* read flag for no side noise shape */
             st->hFdCngDec->hFdCngCom->no_side_flag = get_next_indice_fx( st, 1 );
             move16();
diff --git a/lib_dec/ivas_ism_metadata_dec_fx.c b/lib_dec/ivas_ism_metadata_dec_fx.c
index 2c13e25c8a82c193a3011c50d6e41ca0da6fe483..54cc5da15e24d25f025530478d84a4674a0c5ad2 100644
--- a/lib_dec/ivas_ism_metadata_dec_fx.c
+++ b/lib_dec/ivas_ism_metadata_dec_fx.c
@@ -30,6 +30,7 @@
 
 *******************************************************************************************************/
 
+#include "move.h"
 #include <stdint.h>
 #include "options.h"
 #include "ivas_cnst.h"
@@ -1247,21 +1248,47 @@ void ivas_ism_metadata_sid_dec_fx(
             {
                 IF( EQ_16( ch, *sce_id_dtx ) )
                 {
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+                    FOR( i = 0; i < MDCT_ST_DTX_NUM_COHERENCE_BANDS; i++ )
+                    {
+                        hSCE[ch]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx[i] = 32767;
+                    }
+
+#else
                     hSCE[ch]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx = 32767; // 1.0f in Q15
                     move16();
+#endif
                     CONTINUE;
                 }
 
                 idx = get_next_indice_fx( st0, nBits_coh );
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+                hSCE[ch]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx[0] = get_next_index_4_by_15[idx]; // Q15
+                move16();
+                FOR( i = 1; i < MDCT_ST_DTX_NUM_COHERENCE_BANDS; i++ )
+                {
+                    hSCE[ch]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx[i] = hSCE[ch]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx[0];
+                    move16();
+                }
+#else
                 hSCE[ch]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx = div_s( idx, sub( ( shl( 1, nBits_coh ) ), 1 ) ); // Q15
                 move16();
+#endif
             }
         }
 
-        if ( EQ_32( ism_mode, ISM_MODE_PARAM ) )
+        IF( EQ_32( ism_mode, ISM_MODE_PARAM ) )
         {
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+            FOR( i = 0; i < MDCT_ST_DTX_NUM_COHERENCE_BANDS; i++ )
+            {
+                hSCE[*sce_id_dtx]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx[i] = hSCE[!*sce_id_dtx]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx[i];
+                move16();
+            }
+#else
             hSCE[*sce_id_dtx]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx = hSCE[!*sce_id_dtx]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx;
             move16();
+#endif
         }
 
         /*----------------------------------------------------------------*
diff --git a/lib_dec/ivas_ism_param_dec_fx.c b/lib_dec/ivas_ism_param_dec_fx.c
index 1c94fbe394e3fba0e037800d8b1b54b06ef322bb..430e087130f0f45f4ea51f03ff0e18ef0204ea29 100644
--- a/lib_dec/ivas_ism_param_dec_fx.c
+++ b/lib_dec/ivas_ism_param_dec_fx.c
@@ -1818,8 +1818,12 @@ void ivas_param_ism_params_to_masa_param_mapping_fx(
 
     IF( st_ivas->hISMDTX.dtx_flag )
     {
-        Word32 energy_ratio_fx;                                                                                                                                                /* Q30 */
+        Word32 energy_ratio_fx; /* Q30 */
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+        energy_ratio_fx = L_mult0( st_ivas->hSCE[0]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx[0], st_ivas->hSCE[0]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx[0] ); /* Q15 + Q15 -> Q30 */
+#else
         energy_ratio_fx = L_mult0( st_ivas->hSCE[0]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx, st_ivas->hSCE[0]->hCoreCoder[0]->hFdCngDec->hFdCngCom->coherence_fx ); /* Q15 + Q15 -> Q30 */
+#endif
 
         hSpatParamRendCom->numSimultaneousDirections = 1;
         move16();
diff --git a/lib_dec/ivas_stereo_mdct_stereo_dec_fx.c b/lib_dec/ivas_stereo_mdct_stereo_dec_fx.c
index 43dc48edfad2aa4e00376d17c73518e183879561..efea57f4daaf084e5dcd8fe0f32c14a8d9bd9340 100644
--- a/lib_dec/ivas_stereo_mdct_stereo_dec_fx.c
+++ b/lib_dec/ivas_stereo_mdct_stereo_dec_fx.c
@@ -634,7 +634,11 @@ void synchonize_channels_mdct_sid_fx(
             move16();
             sts[1]->bwidth = sts[0]->bwidth;
             move16();
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+            sts[0]->hFdCngDec->hFdCngCom->coherence_fx[0] = sts[1]->hFdCngDec->hFdCngCom->coherence_fx[0]; /* coherence is stored in sts[1] - see ivas_decision_matrix_dec() */
+#else
             sts[0]->hFdCngDec->hFdCngCom->coherence_fx = sts[1]->hFdCngDec->hFdCngCom->coherence_fx; /* coherence is stored in sts[1] - see ivas_decision_matrix_dec() */
+#endif
             move16();
             sts[0]->hFdCngDec->hFdCngCom->no_side_flag = sts[1]->hFdCngDec->hFdCngCom->no_side_flag;
             move16();
diff --git a/lib_enc/fd_cng_enc_fx.c b/lib_enc/fd_cng_enc_fx.c
index 6834958d1b0937c9e8590b4c2a97a335fe0474db..0bbbdcbd7ea7b30f7e379e0bb65d68f48999bec5 100644
--- a/lib_enc/fd_cng_enc_fx.c
+++ b/lib_enc/fd_cng_enc_fx.c
@@ -2,12 +2,17 @@
     EVS Codec 3GPP TS26.452 Aug 12, 2021. Version 16.3.0
   ====================================================================================*/
 
+#include "wmc_auto.h"
 #include <assert.h>
 #include "stl.h"
 #include "options.h"
 #include "cnst.h"
+#include "ivas_cnst.h"
 #include "stl.h"
 #include "rom_com.h"
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+#include "ivas_rom_com.h"
+#endif
 #include "rom_enc.h"
 #include "prot_fx.h"
 #include "prot_fx_enc.h"
@@ -144,8 +149,16 @@ void initFdCngEnc_fx(
     hsEnc->msPeriodogBufPtr = 0;
     move16();
     set32_fx( hsEnc->msPsdSecondMoment_fx, 0, NPART );
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    FOR( Word16 i = 0; i < MDCT_ST_DTX_NUM_COHERENCE_BANDS; i++ )
+    {
+        set32_fx( hsEnc->mem_coherence_fx[i], EPSILON_FX, 4 );
+        set16_fx( hsEnc->mem_coherence_exp[i], 0, 4 );
+    }
+#else
     set32_fx( hsEnc->mem_coherence_fx, EPSILON_FX, 4 );
     set16_fx( hsEnc->mem_coherence_exp, 0, 4 );
+#endif
 
     return;
 }
@@ -2660,8 +2673,16 @@ void stereoFdCngCoherence_fx(
 
     IF( NE_16( last_element_mode, IVAS_CPE_MDCT ) )
     {
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+        FOR( i = 0; i < MDCT_ST_DTX_NUM_COHERENCE_BANDS; i++ )
+        {
+            set32_fx( sts[0]->hFdCngEnc->mem_coherence_fx[i], EPSILON_FX, 4 );
+            set16_fx( sts[0]->hFdCngEnc->mem_coherence_exp[i], 0, 4 );
+        }
+#else
         set32_fx( sts[0]->hFdCngEnc->mem_coherence_fx, EPSILON_FX, 4 );
         set16_fx( sts[0]->hFdCngEnc->mem_coherence_exp, 0, 4 );
+#endif
     }
     test();
     test();
@@ -2726,8 +2747,96 @@ void stereoFdCngCoherence_fx(
 
     pt_fftL = fft_buf_fx[0];
     pt_fftR = fft_buf_fx[1];
+#ifndef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
     mem = sts[0]->hFdCngEnc->mem_coherence_fx; /* exp(sts[0]->hFdCngEnc->mem_coherence_exp) */
     mem_exp = sts[0]->hFdCngEnc->mem_coherence_exp;
+#endif
+
+    /* only estimate coherence in inactive frames (or in the first 50 frames to build an initial value) */
+    test();
+    test();
+    test();
+    IF( NE_16( ( LE_32( sts[0]->ini_frame, 50 ) || ( EQ_16( sts[0]->vad_flag, 0 ) && EQ_16( sts[1]->vad_flag, 0 ) ) ), 0 ) )
+    {
+        return;
+    }
+
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    FOR( i_subfr = 0; i_subfr < 2; i_subfr++ )
+    {
+        Word16 band_len_cum;
+
+        band_len_cum = 0;
+        move16();
+        i = MDCT_ST_DTX_FIRST_BAND_OFFSET;
+        move16();
+
+        FOR( Word16 b = 0; b < MDCT_ST_DTX_NUM_COHERENCE_BANDS; b++ )
+        {
+            Word16 sqr_inp, temp, sqr_out, sqr_inp_exp;
+            Word32 sqr_inp32;
+            band_len_cum += mdct_stereo_dtx_coherence_bandlengths[b];
+            move16();
+            cr = ci = eL = eR = EPSILON_FX;
+            move32();
+            move32();
+            move32();
+            move32();
+            cr_exp = ci_exp = eL_exp = eR_exp = 0;
+            move16();
+            move16();
+            move16();
+            move16();
+
+            mem = sts[0]->hFdCngEnc->mem_coherence_fx[b];
+            mem_exp = sts[0]->hFdCngEnc->mem_coherence_exp[b];
+
+            /* for last band, we need to make adjustments to fit with the FFT buffer layout */
+            /* do the calculations for fftbin 0 (not anymore as it is skipped - we only calculate coherence above the 2nd bin) and L_FFT/2 outside the loop - imaginary part is always zero there, but not part of the buffer */
+            IF( EQ_16( b, sub( MDCT_ST_DTX_NUM_COHERENCE_BANDS, 1 ) ) )
+            {
+                /* this calculates values for fft bin at L_FFT/2 - no imaginary value there, not even part of the array */
+                cr = BASOP_Util_Add_Mant32Exp( cr, cr_exp, L_mult( pt_fftL[L_FFT / 2], pt_fftR[L_FFT / 2] ), shl( fft_exp, 1 ), &cr_exp ); /* exp(cr_exp) */
+                eL = BASOP_Util_Add_Mant32Exp( eL, eL_exp, L_mult( pt_fftL[L_FFT / 2], pt_fftL[L_FFT / 2] ), shl( fft_exp, 1 ), &eL_exp ); /* exp(eL_exp) */
+                eR = BASOP_Util_Add_Mant32Exp( eR, eR_exp, L_mult( pt_fftR[L_FFT / 2], pt_fftR[L_FFT / 2] ), shl( fft_exp, 1 ), &eR_exp ); /* exp(eR_exp) */
+
+                /* skip last fft bin (fs/2 Hz) bin in the loop later */
+                band_len_cum = sub( band_len_cum, 1 );
+            }
+
+            FOR( ; i < band_len_cum; i++ )
+            {
+                cr = BASOP_Util_Add_Mant32Exp( cr, cr_exp, L_add( L_mult( pt_fftL[i], pt_fftR[i] ), L_mult( pt_fftL[L_FFT - i], pt_fftR[L_FFT - i] ) ), shl( fft_exp, 1 ), &cr_exp );  /* exp(cr_exp) */
+                ci = BASOP_Util_Add_Mant32Exp( ci, ci_exp, L_add( L_mult( -pt_fftL[i], pt_fftR[L_FFT - i] ), L_mult( pt_fftL[L_FFT - i], pt_fftR[i] ) ), shl( fft_exp, 1 ), &ci_exp ); /* exp(ci_exp) */
+                eL = BASOP_Util_Add_Mant32Exp( eL, eL_exp, L_add( L_mult( pt_fftL[i], pt_fftL[i] ), L_mult( pt_fftL[L_FFT - i], pt_fftL[L_FFT - i] ) ), shl( fft_exp, 1 ), &eL_exp );  /* exp(eL_exp) */
+                eR = BASOP_Util_Add_Mant32Exp( eR, eR_exp, L_add( L_mult( pt_fftR[i], pt_fftR[i] ), L_mult( pt_fftR[L_FFT - i], pt_fftR[L_FFT - i] ) ), shl( fft_exp, 1 ), &eR_exp );  /* exp(eR_exp) */
+            }
+
+            mem[0] = BASOP_Util_Add_Mant32Exp( Mpy_32_16_1( mem[0], 31129 /*0.95f*/ ), mem_exp[0], Mpy_32_16_1( cr, 1638 /*0.05f*/ ), cr_exp, &mem_exp[0] ); /* exp(mem_exp[0]) */
+            move32();
+            mem[1] = BASOP_Util_Add_Mant32Exp( Mpy_32_16_1( mem[1], 31129 /*0.95f*/ ), mem_exp[1], Mpy_32_16_1( ci, 1638 /*0.05f*/ ), ci_exp, &mem_exp[1] ); /* exp(mem_exp[1]) */
+            move32();
+            mem[2] = BASOP_Util_Add_Mant32Exp( Mpy_32_16_1( mem[2], 31129 /*0.95f*/ ), mem_exp[2], Mpy_32_16_1( eL, 1638 /*0.05f*/ ), eL_exp, &mem_exp[2] ); /* exp(mem_exp[2]) */
+            move32();
+            mem[3] = BASOP_Util_Add_Mant32Exp( Mpy_32_16_1( mem[3], 31129 /*0.95f*/ ), mem_exp[3], Mpy_32_16_1( eR, 1638 /*0.05f*/ ), eR_exp, &mem_exp[3] ); /* exp(mem_exp[3]) */
+            move32();
+
+            /* could be done outside the loop, as the second assignment overwrites the first, but this would mean a second loop over bands */
+            /* For orientation, in float, this is "sts[0]->hFdCngEnc->hFdCngCom->coherence[b] = sqrtf( ( mem[0] * mem[0] + mem[1] * mem[1] ) / ( mem[2] * mem[3] ) );" */
+            sqr_inp32 = BASOP_Util_Add_Mant32Exp( Mpy_32_32( mem[0], mem[0] ), shl( mem_exp[0], 1 ), Mpy_32_32( mem[1], mem[1] ), shl( mem_exp[1], 1 ), &sqr_inp_exp ); /* exp(sqr_inp_exp) */
+            sqr_inp = BASOP_Util_Divide3232_Scale( sqr_inp32, Mpy_32_32( mem[2], mem[3] ), &temp );
+            sqr_inp_exp = add( temp, sub( sqr_inp_exp, add( mem_exp[2], mem_exp[3] ) ) );
+            sqr_out = Sqrt16( sqr_inp, &sqr_inp_exp );
+
+            sts[0]->hFdCngEnc->hFdCngCom->coherence_fx[b] = shl_sat( sqr_out, sqr_inp_exp ); // Q15 expected.
+            move16();
+        }
+
+        pt_fftL += L_FFT;
+        pt_fftR += L_FFT;
+    }
+
+#else
     FOR( i_subfr = 0; i_subfr < 2; i_subfr++ )
     {
         cr = ci = eL = eR = EPSILON_FX;
@@ -2769,7 +2878,9 @@ void stereoFdCngCoherence_fx(
         pt_fftL += L_FFT;
         pt_fftR += L_FFT;
     }
+#endif
 
+#ifndef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
     Word16 sqr_inp, temp, sqr_out, sqr_inp_exp;
     Word32 sqr_inp32 = BASOP_Util_Add_Mant32Exp( Mpy_32_32( mem[0], mem[0] ), shl( mem_exp[0], 1 ), Mpy_32_32( mem[1], mem[1] ), shl( mem_exp[1], 1 ), &sqr_inp_exp ); /* exp(sqr_inp_exp) */
     sqr_inp = BASOP_Util_Divide3232_Scale( sqr_inp32, Mpy_32_32( mem[2], mem[3] ), &temp );
@@ -2777,6 +2888,7 @@ void stereoFdCngCoherence_fx(
     sqr_out = Sqrt16( sqr_inp, &sqr_inp_exp );
     sts[0]->hFdCngEnc->hFdCngCom->coherence_fx = shl_sat( sqr_out, sqr_inp_exp ); // Q15 expected.
     move16();
+#endif
     return;
 }
 
@@ -3050,7 +3162,11 @@ void FdCngEncodeMDCTStereoSID_fx(
     }
 
     /* quantize channel coherence */
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    coh_idx = mult_r( sts[0]->hFdCngEnc->hFdCngCom->coherence_fx[0], 15 );
+#else
     coh_idx = mult_r( sts[0]->hFdCngEnc->hFdCngCom->coherence_fx, 15 );
+#endif
     coh_idx = s_max( 0, s_min( coh_idx, 15 ) );
 
     /* ---- Write SID bitstream ---- */
@@ -3084,8 +3200,18 @@ void FdCngEncodeMDCTStereoSID_fx(
         push_indice( sts[ch]->hBstr, IND_ENERGY, gain_idx[ch], 7 );
     }
 
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    /* write the four additional coherence values */
+    FOR( Word16 b = 1; b < MDCT_ST_DTX_NUM_COHERENCE_BANDS; b++ )
+    {
+        coh_idx = mult_r( sts[0]->hFdCngEnc->hFdCngCom->coherence_fx[b], 15 );
+        coh_idx = s_max( 0, s_min( coh_idx, 15 ) );
+        push_indice( sts[1]->hBstr, IND_ENERGY, coh_idx, 4 );
+    }
+#else
     /* pad with zeros to reach common SID frame size */
     push_indice( sts[1]->hBstr, IND_ENERGY, 0, ( IVAS_SID_5k2 - 4400 ) / FRAMES_PER_SEC );
+#endif
 
     return;
 }
@@ -3289,10 +3415,17 @@ void FdCngEncodeDiracMDCTStereoSID_fx(
         lpc_from_spectrum( hFdCngCom, hFdCngEnc->startBandDec, hFdCngEnc->stopFFTbinDec, sts[ch]->preemph_fac );
         sts[ch]->hDtxEnc->last_CNG_L_frame = sts[ch]->L_frame;
     }
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    sts[0]->hFdCngEnc->hFdCngCom->coherence_fx[0] = 0;
+    move16();
+    sts[1]->hFdCngEnc->hFdCngCom->coherence_fx[0] = 0;
+    move16();
+#else
     sts[0]->hFdCngEnc->hFdCngCom->coherence_fx = 0;
     move16();
     sts[1]->hFdCngEnc->hFdCngCom->coherence_fx = 0;
     move16();
+#endif
 
     /* ---- Write SID bitstream ---- */
 
diff --git a/lib_enc/stat_enc.h b/lib_enc/stat_enc.h
index e20c06fd45eee9b8b8b1158c0df4b16d9722d4a7..44125a717ff581be9d35dd2ce4b17b263ef06afb 100644
--- a/lib_enc/stat_enc.h
+++ b/lib_enc/stat_enc.h
@@ -397,8 +397,13 @@ typedef struct fd_cng_enc_structure
     Word16 msLogPeriodog_fx[NPART];
     Word16 msLogNoiseEst_fx[NPART];
     Word32 msLogNoiseEst_32fx[NPART]; /*IVAS: Q25*/
+#ifdef NONBE_MDCT_ST_DTX_FIX_SUBOPT_SPATIAL_CNG
+    Word32 mem_coherence_fx[MDCT_ST_DTX_NUM_COHERENCE_BANDS][4];
+    Word16 mem_coherence_exp[MDCT_ST_DTX_NUM_COHERENCE_BANDS][4];
+#else
     Word32 mem_coherence_fx[4];
     Word16 mem_coherence_exp[4];
+#endif
 
 } FD_CNG_ENC, *HANDLE_FD_CNG_ENC;