diff --git a/lib_com/options.h b/lib_com/options.h
index baecc29e39933e9469a07debae5921250d1387f8..1b0440bbcd5345160910afad7356f0b173e107cb 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -102,6 +102,7 @@
 #define HARMONIZE_TBE2                                  /* VA: basop issue 2399: Remove duplicated code: TBE, step 2 */
 #define HARM_FD_BWE                                     /* VA: harmonize core-coder FD BWE function duplications */
 #define FIX_2411_Harmonize_TNSANALYSIS_DETECTTNSFILT    /* FhG: basop issue 2411: harmonize TNSAnalysis*_fx(), DetectTnsFilt*_fx()*/        
+#define HARMONIZE_READ_DECODE_TNS                       /* FhG basop 2389: Harm between two pairs of functions. */
 
 /* #################### End BE switches ################################## */
 
diff --git a/lib_com/parameter_bitmaping_fx.c b/lib_com/parameter_bitmaping_fx.c
index 4225879e6b20e56584e35c4bc40240cfc0112337..5a2f8ccfe640147dd4798ff6246940ac0a119ee9 100644
--- a/lib_com/parameter_bitmaping_fx.c
+++ b/lib_com/parameter_bitmaping_fx.c
@@ -228,8 +228,15 @@ void SetParameters_fx(
             IF( s_and( param->pSubParamBitMap != NULL, value > 0 ) )
             {
                 pTmp = pParameter;
+#ifdef HARMONIZE_READ_DECODE_TNS
                 if ( pSubStruct != NULL )
+                {
                     pTmp = pSubStruct;
+                }
+#else
+                if ( pSubStruct != NULL )
+                    pTmp = pSubStruct;
+#endif
                 SetParameters( param->pSubParamBitMap, value, pTmp, pStream, pnSize );
             }
         }
diff --git a/lib_com/prot_fx.h b/lib_com/prot_fx.h
index c9ad7fcff8339eec8ea1d878a3770ed519a1784b..d3d45ab1d6ba2d9fccb8187c0f4b35566df10fae 100644
--- a/lib_com/prot_fx.h
+++ b/lib_com/prot_fx.h
@@ -7489,8 +7489,8 @@ ivas_error core_switching_post_dec_fx(
     Word32 *output_fx,        /* i/o: LB synth/upsampled LB synth                                                    Q11*/
     Word32 output_mem_fx32[], /* i  : OLA memory from last TCX/HQ frame                                               Qx*/
 #else
-    Word32 *output_fx,           /* i/o: LB synth/upsampled LB synth                                                     Q4*/
-    Word16 output_mem_fx[],      /* i  : OLA memory from last TCX/HQ frame                                               Qx*/
+    Word32 *output_fx,      /* i/o: LB synth/upsampled LB synth                                                     Q4*/
+    Word16 output_mem_fx[], /* i  : OLA memory from last TCX/HQ frame                                               Qx*/
 #endif
     const Word16 use_cldfb_for_dft,     /* i  : flag to use of CLDFB for DFT Stereo                                             Q0*/
     const Word16 output_frame,          /* i  : frame length                                                                    Q0*/
@@ -8291,7 +8291,21 @@ void tcx_hm_modify_envelope(
     Word32 env[],     /* i/o: envelope                          Q16 */
     Word16 L_frame    /* i:   number of spectral lines          Q0  */
 );
+#ifdef HARMONIZE_READ_DECODE_TNS
+void ReadTnsData_fx(
+    STnsConfig const *pTnsConfig,
+    Decoder_State *st,
+    Word16 *pnBits,
+    Word16 *stream,
+    Word16 *pnSize );
+
+Word16 DecodeTnsData_fx(
+    STnsConfig const *pTnsConfig,
+    Word16 const *stream, /*Q0*/
+    Word16 *pnSize,       /*Q0*/
+    STnsData *pTnsData );
 
+#else
 Word16 ReadTnsData(
     STnsConfig const *pTnsConfig,
     Decoder_State *st,
@@ -8318,6 +8332,7 @@ Word16 DecodeTnsData_ivas_fx(
     Word16 *pnSize,
     STnsData *pTnsData );
 
+#endif
 void GetParameters(
     ParamsBitMap const *paramsBitMap,
     const Word16 nParams,
@@ -10981,12 +10996,6 @@ void EncodeTnsData(
     Word16 *pnBits                /* o  : number of written bits            */
 );
 
-Word16 DecodeTnsData_ivas(
-    STnsConfig const *pTnsConfig,
-    const Word16 *stream,
-    Word16 *pnSize,
-    STnsData *pTnsData );
-
 void WriteTnsData(
     const STnsConfig *pTnsConfig, /* i  : TNS Configuration struct          */
     const Word16 *stream,         /* i  : internal data stream              */
@@ -10994,7 +11003,7 @@ void WriteTnsData(
     BSTR_ENC_HANDLE hBstr,        /* o  : bitstream                         */
     Word16 *pnBits                /* o  : number of written bits            */
 );
-
+#ifndef HARMONIZE_READ_DECODE_TNS
 void ReadTnsData_ivas(
     STnsConfig const *pTnsConfig,
     Decoder_State *st,
@@ -11002,6 +11011,13 @@ void ReadTnsData_ivas(
     Word16 *stream,
     Word16 *pnSize );
 
+Word16 DecodeTnsData_ivas(
+    STnsConfig const *pTnsConfig,
+    const Word16 *stream,
+    Word16 *pnSize,
+    STnsData *pTnsData );
+
+#endif // HARMONIZE_READ_DECODE_TNS
 void analysisCldfbEncoder_ivas_fx(
     Encoder_State *st,       /* i/o: encoder state structure   */
     Word32 *timeIn,          /*q11*/
diff --git a/lib_dec/dec_prm_fx.c b/lib_dec/dec_prm_fx.c
index 41a2e9842cd2657b9f28f019e4a75462e9e93f22..420c20dbfb65afb13addc582fa0acac280d00d82 100644
--- a/lib_dec/dec_prm_fx.c
+++ b/lib_dec/dec_prm_fx.c
@@ -394,7 +394,13 @@ void getTCXparam_fx(
                 }
                 ELSE
                 {
+#ifdef HARMONIZE_READ_DECODE_TNS
+
+                    ReadTnsData_fx( st->hTcxCfg->pCurrentTnsConfig, st0, &nTnsBits, prm + j, &nTnsParams );
+#else
+
                     ReadTnsData_ivas_fx( st->hTcxCfg->pCurrentTnsConfig, st0, &nTnsBits, prm + j, &nTnsParams );
+#endif // HARMONIZE_READ_DECODE_TNS
                 }
                 hTcxDec->tnsActive[k] = 0; // Q0
                 move16();
@@ -1351,7 +1357,11 @@ void dec_prm_fx(
         IF( st->hTcxCfg->fIsTNSAllowed )
         {
             SetTnsConfig( st->hTcxCfg, 1, (Word16) EQ_16( st->last_core_from_bs, ACELP_CORE ) );
+#ifdef HARMONIZE_READ_DECODE_TNS
+            ReadTnsData_fx( st->hTcxCfg->pCurrentTnsConfig, st, &nTnsBits, prm + j, &nTnsParams );
+#else
             ReadTnsData( st->hTcxCfg->pCurrentTnsConfig, st, &nTnsBits, prm + j, &nTnsParams );
+#endif //  HARMONIZE_READ_DECODE_TNS
 
             j = add( j, nTnsParams ); // Q0
         }
@@ -1675,8 +1685,13 @@ void dec_prm_fx(
                 test();
                 test();
                 SetTnsConfig( st->hTcxCfg, 0, ( st->last_core_from_bs == ACELP_CORE ) && ( k == 0 ) );
-
+#ifdef HARMONIZE_READ_DECODE_TNS
+                ReadTnsData_fx( st->hTcxCfg->pCurrentTnsConfig, st, &nTnsBits, prm + j, &nTnsParams );
+#else
                 ReadTnsData( st->hTcxCfg->pCurrentTnsConfig, st, &nTnsBits, prm + j, &nTnsParams );
+#endif // DEBUG
+
+
                 j = add( j, nTnsParams );
             }
 
diff --git a/lib_dec/dec_tcx_fx.c b/lib_dec/dec_tcx_fx.c
index 8482ef78b9c4ad53e51af924cd1bfcd8edce0db6..0b954c17c41712a68c250b803f9d1ea0431944ea 100644
--- a/lib_dec/dec_tcx_fx.c
+++ b/lib_dec/dec_tcx_fx.c
@@ -297,11 +297,17 @@ void decoder_tcx_fx(
     IF( ( bfi == 0 ) && ( hTcxCfg->fIsTNSAllowed != 0 ) )
     {
         cast16();
-
+#ifdef HARMONIZE_READ_DECODE_TNS
+        fUseTns = (Word8) DecodeTnsData_fx( hTcxCfg->pCurrentTnsConfig,
+                                            prm_tns,
+                                            &tnsSize,
+                                            &tnsData );
+#else
         fUseTns = (Word8) DecodeTnsData( hTcxCfg->pCurrentTnsConfig,
                                          prm_tns,
                                          &tnsSize,
                                          &tnsData );
+#endif // HARMONIZE_READ_DECODE_TNS
     }
     ELSE
     {
@@ -4200,7 +4206,12 @@ void decoder_tcx_invQ_fx(
     test();
     IF( !bfi && hTcxCfg->fIsTNSAllowed )
     {
+#ifdef HARMONIZE_READ_DECODE_TNS
+        *fUseTns = DecodeTnsData_fx( hTcxCfg->pCurrentTnsConfig, prm_tns, &tnsSize, tnsData );
+#else
         *fUseTns = DecodeTnsData_ivas_fx( hTcxCfg->pCurrentTnsConfig, prm_tns, &tnsSize, tnsData );
+#endif // HARMONIZE_READ_DECODE_TNS
+
         move16();
     }
     ELSE
diff --git a/lib_dec/tns_base_dec_fx.c b/lib_dec/tns_base_dec_fx.c
index e245a4674acca3a9eed93f2b189caec8036ade81..44d18ccb2a4dda6daaee40b9b6266bf0fd4473e8 100644
--- a/lib_dec/tns_base_dec_fx.c
+++ b/lib_dec/tns_base_dec_fx.c
@@ -21,6 +21,119 @@ typedef Word32 ( *TLinearPredictionFilter )( Word16 order, Word16 const parCoeff
 /********************************/
 /*      Interface functions     */
 /********************************/
+
+
+#ifdef HARMONIZE_READ_DECODE_TNS
+/*---------------------------------------------------------------------*
+ * ReadTnsData()
+ *
+ *
+ *---------------------------------------------------------------------*/
+void ReadTnsData_fx(
+    STnsConfig const *pTnsConfig,
+    Decoder_State *st,
+    Word16 *pnBits, /*Q0*/
+    Word16 *stream, /*Q0*/
+    Word16 *pnSize  /*Q0*/
+)
+{
+    Word16 start_bit_pos;
+
+    move16();
+    start_bit_pos = st->next_bit_pos;
+
+    IF( GT_16( pTnsConfig->nMaxFilters, 1 ) )
+    {
+        IF( pTnsConfig->allowTnsOnWhite )
+        {
+            IF( LT_16( pTnsConfig->iFilterBorders[0], 512 ) )
+            {
+                ReadFromBitstream_fx( &tnsEnabledOnWhiteSWBTCX10BitMap, 1, st, &stream, pnSize );
+            }
+            ELSE
+            {
+                ReadFromBitstream_fx( &tnsEnabledOnWhiteSWBTCX20BitMap, 1, st, &stream, pnSize );
+            }
+        }
+        ELSE
+        {
+
+            IF( LT_16( pTnsConfig->iFilterBorders[0], 512 ) )
+            {
+                ReadFromBitstream_fx( &tnsEnabledSWBTCX10BitMap, 1, st, &stream, pnSize );
+            }
+            ELSE
+            {
+                ReadFromBitstream_fx( &tnsEnabledSWBTCX20BitMap, 1, st, &stream, pnSize );
+            }
+        }
+    }
+    ELSE
+    {
+        ReadFromBitstream_fx( &tnsEnabledWBTCX20BitMap, 1, st, &stream, pnSize );
+    }
+
+    move16();
+    *pnBits = sub( st->next_bit_pos, start_bit_pos );
+}
+
+/*---------------------------------------------------------------------*
+ * DecodeTnsData()
+ *
+ *
+ *---------------------------------------------------------------------*/
+Word16 DecodeTnsData_fx(
+    STnsConfig const *pTnsConfig,
+    Word16 const *stream, /*Q0*/
+    Word16 *pnSize,       /*Q0*/
+    STnsData *pTnsData )
+{
+    Word16 result;
+
+    ResetTnsData( pTnsData );
+
+    IF( GT_16( pTnsConfig->nMaxFilters, 1 ) )
+    {
+
+        IF( pTnsConfig->allowTnsOnWhite )
+        {
+            IF( LT_16( pTnsConfig->iFilterBorders[0], 512 ) )
+            {
+                SetParameters_fx( &tnsEnabledOnWhiteSWBTCX10BitMap, 1, pTnsData, &stream, pnSize );
+            }
+            ELSE
+            {
+                SetParameters_fx( &tnsEnabledOnWhiteSWBTCX20BitMap, 1, pTnsData, &stream, pnSize );
+            }
+        }
+        ELSE
+        {
+
+            IF( LT_16( pTnsConfig->iFilterBorders[0], 512 ) )
+            {
+                SetParameters_fx( &tnsEnabledSWBTCX10BitMap, 1, pTnsData, &stream, pnSize );
+            }
+            ELSE
+            {
+                SetParameters_fx( &tnsEnabledSWBTCX20BitMap, 1, pTnsData, &stream, pnSize );
+            }
+        }
+    }
+    ELSE
+    {
+        SetParameters_fx( &tnsEnabledWBTCX20BitMap, 1, pTnsData, &stream, pnSize );
+    }
+
+    move16();
+    result = FALSE;
+    if ( pTnsData->nFilters > 0 )
+    {
+        move16();
+        result = TRUE;
+    }
+    return result;
+}
+#else
 /*---------------------------------------------------------------------*
  * ReadTnsData()
  *
@@ -216,3 +329,6 @@ Word16 DecodeTnsData_ivas_fx(
 
     return result;
 }
+
+
+#endif // HARMONIZE_READ_DECODE_TNS