diff --git a/lib_com/ivas_prot.h b/lib_com/ivas_prot.h
index 5645b8e9bf46fa6b5903314d7975da46e8f52d1f..562d46a268b088ec0bba1bb06ef638725594b20d 100644
--- a/lib_com/ivas_prot.h
+++ b/lib_com/ivas_prot.h
@@ -223,8 +223,12 @@ ivas_error pre_proc_front_ivas(
     const int16_t front_vad_flag,                               /* i  : front-VAD flag to overwrite VAD decision   */
     const int16_t force_front_vad,                              /* i  : flag to force VAD decision                 */
     const int16_t front_vad_dtx_flag,                           /* i  : front-VAD DTX flag to overwrite VAD decision*/
+#ifdef LOW_RATE_TRANS_CORE_CODER
+    const int32_t ivas_total_brate                             /* i  : IVAS total bitrate                         */
+#else
     const int32_t ivas_total_brate,                             /* i  : IVAS total bitrate                         */
     const int16_t ivas_format                                   /* i  : IVAS format                                */
+#endif
 );
 
 ivas_error pre_proc_ivas(
diff --git a/lib_com/options.h b/lib_com/options.h
index a5a6a8cfb8f734aef92e375d3cafc964d6a18e4e..746e650c58e0a3a3efdf5fc012ff40b6568ea517 100755
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -148,6 +148,8 @@
 #endif
 
 
+#define LOW_RATE_TRANS_CORE_CODER                       /* Eri: Activate low-rate-encoding-of-transients contribution for core coder, affects MC, MASA and SBA */
+
 #define FIX_197_CREND_INTERFACE 
 
 #define FIX_MEMORY_COUNTING_HRTF_BINARY_FILE
diff --git a/lib_enc/ivas_core_pre_proc_front.c b/lib_enc/ivas_core_pre_proc_front.c
index be28d0ee7fe1bb726260b5815b312c8e773139a7..000fbab33ebbabbaaba7787b9a47abc6181da856 100644
--- a/lib_enc/ivas_core_pre_proc_front.c
+++ b/lib_enc/ivas_core_pre_proc_front.c
@@ -107,8 +107,14 @@ ivas_error pre_proc_front_ivas(
     const int16_t front_vad_flag,                              /* i  : front-VAD flag to overwrite VAD decision */
     const int16_t force_front_vad,                             /* i  : flag to force VAD decision               */
     const int16_t front_vad_dtx_flag,                          /* i  : front-VAD DTX flag to overwrite VAD decision*/
-    const int32_t ivas_total_brate,                            /* i  : IVAS total bitrate - for setting the DTX */
-    const int16_t ivas_format )
+#ifdef LOW_RATE_TRANS_CORE_CODER
+    const int32_t ivas_total_brate /* i  : IVAS total bitrate - for setting the DTX */
+#else
+    const int32_t ivas_total_brate, /* i  : IVAS total bitrate - for setting the DTX */
+    const int16_t ivas_format       /* i  : IVAS format                              */
+#endif
+
+)
 {
     float *inp_12k8, *new_inp_12k8;        /* pointers to current frame and new data       */
     float *wsp;                            /* weighted input signal buffer                 */
@@ -805,7 +811,11 @@ ivas_error pre_proc_front_ivas(
             }
         }
         /* Switch to ACELP for non-harmonic transient signals */
+#ifdef LOW_RATE_TRANS_CORE_CODER
+        else if ( ( ( element_mode >= IVAS_CPE_DFT && element_brate <= IVAS_16k4 ) || ( element_mode == IVAS_SCE && element_brate < SCE_SMC_THR ) ) && ( loc_harm[0] != 1 ) && smc_dec == MUSIC )
+#else
         else if ( ( ( ivas_format == STEREO_FORMAT && element_brate <= IVAS_16k4 ) || ( ivas_format == ISM_FORMAT && element_brate < SCE_SMC_THR ) ) && ( loc_harm[0] != 1 ) && smc_dec == MUSIC )
+#endif
         {
             if ( element_mode == IVAS_SCE )
             {
@@ -820,7 +830,7 @@ ivas_error pre_proc_front_ivas(
                 {
                     if ( smc_dec != SPEECH && transient_analysis( hCPE->hCoreCoder[i]->hTranDet, st->hNoiseEst->cor_map, st->hNoiseEst->multi_harm_limit ) )
                     {
-                        smc_dec = SPEECH; /* overwrite initial music decision, intial SPEECH_MUSIC never changed */
+                        smc_dec = SPEECH; /* overwrite initial music decision, initial SPEECH_MUSIC never changed */
                     }
                 }
             }
diff --git a/lib_enc/ivas_cpe_enc.c b/lib_enc/ivas_cpe_enc.c
index 96cb8fba0b577f0aa3191d9f4db21fc655c0e363..4b734d2653db3c6c8bf9dda023350c33130e2cb5 100644
--- a/lib_enc/ivas_cpe_enc.c
+++ b/lib_enc/ivas_cpe_enc.c
@@ -433,11 +433,19 @@ ivas_error ivas_cpe_enc(
 
     for ( n = 0; n < n_CoreChannels; n++ )
     {
+#ifdef LOW_RATE_TRANS_CORE_CODER
+        error = pre_proc_front_ivas( NULL, hCPE, hCPE->element_brate, nb_bits_metadata, input_frame, n, old_inp_12k8[n], old_inp_16k[n],
+                                     &ener[n], &relE[n], A[n], Aw[n], epsP[n], lsp_new[n], lsp_mid[n],
+                                     &vad_hover_flag[n], &attack_flag[n], realBuffer[n], imagBuffer[n], old_wsp[n], pitch_fr[n], voicing_fr[n], &loc_harm[n], &cor_map_sum[n], &vad_flag_dtx[n], enerBuffer[n],
+                                     fft_buff[n], A[0], lsp_new[0], currFlatness[n], tdm_ratio_idx, fr_bands, Etot_LR, lf_E, localVAD_HE_SAD, band_energies_LR, 0, st_ivas->hSpar != NULL ? st_ivas->hSpar->front_vad_flag : 0, 0, 0,
+                                     ivas_total_brate );
+#else
         error = pre_proc_front_ivas( NULL, hCPE, hCPE->element_brate, nb_bits_metadata, input_frame, n, old_inp_12k8[n], old_inp_16k[n],
                                      &ener[n], &relE[n], A[n], Aw[n], epsP[n], lsp_new[n], lsp_mid[n],
                                      &vad_hover_flag[n], &attack_flag[n], realBuffer[n], imagBuffer[n], old_wsp[n], pitch_fr[n], voicing_fr[n], &loc_harm[n], &cor_map_sum[n], &vad_flag_dtx[n], enerBuffer[n],
                                      fft_buff[n], A[0], lsp_new[0], currFlatness[n], tdm_ratio_idx, fr_bands, Etot_LR, lf_E, localVAD_HE_SAD, band_energies_LR, 0, st_ivas->hSpar != NULL ? st_ivas->hSpar->front_vad_flag : 0, 0, 0,
                                      ivas_total_brate, st_ivas->hEncoderConfig->ivas_format );
+#endif
         if ( error != IVAS_ERR_OK )
         {
             return error;
diff --git a/lib_enc/ivas_ism_enc.c b/lib_enc/ivas_ism_enc.c
index 92435ac7b219799deea1bfb08715479ef3b1aea3..0207961e51930d9d78424c94976a234939ffc7d1 100644
--- a/lib_enc/ivas_ism_enc.c
+++ b/lib_enc/ivas_ism_enc.c
@@ -146,11 +146,19 @@ ivas_error ivas_ism_enc(
          * Front Pre-processing
          *----------------------------------------------------------------*/
 
+#ifdef LOW_RATE_TRANS_CORE_CODER
+        error = pre_proc_front_ivas( hSCE, NULL, hSCE->element_brate, nb_bits_metadata[sce_id], input_frame, 0, old_inp_12k8[sce_id][0], old_inp_16k[sce_id][0],
+                                     &ener[sce_id][0], &relE[sce_id][0], A[sce_id][0], Aw[sce_id][0], epsP[sce_id][0], lsp_new[sce_id][0], lsp_mid[sce_id][0],
+                                     &vad_hover_flag[sce_id][0], &attack_flag[sce_id][0], realBuffer[sce_id][0], imagBuffer[sce_id][0], old_wsp[sce_id][0], pitch_fr[sce_id][0], voicing_fr[sce_id][0], &loc_harm[sce_id][0], &cor_map_sum[sce_id][0], &vad_flag_dtx[sce_id][0], enerBuffer[sce_id][0],
+                                     fft_buff[sce_id][0], A[sce_id][0], lsp_new[sce_id][0], currFlatness[0], 0, fr_bands, Etot_LR, lf_E, localVAD_HE_SAD, NULL, 0, 0, 0, 0,
+                                     st_ivas->hEncoderConfig->ivas_total_brate );
+#else
         error = pre_proc_front_ivas( hSCE, NULL, hSCE->element_brate, nb_bits_metadata[sce_id], input_frame, 0, old_inp_12k8[sce_id][0], old_inp_16k[sce_id][0],
                                      &ener[sce_id][0], &relE[sce_id][0], A[sce_id][0], Aw[sce_id][0], epsP[sce_id][0], lsp_new[sce_id][0], lsp_mid[sce_id][0],
                                      &vad_hover_flag[sce_id][0], &attack_flag[sce_id][0], realBuffer[sce_id][0], imagBuffer[sce_id][0], old_wsp[sce_id][0], pitch_fr[sce_id][0], voicing_fr[sce_id][0], &loc_harm[sce_id][0], &cor_map_sum[sce_id][0], &vad_flag_dtx[sce_id][0], enerBuffer[sce_id][0],
                                      fft_buff[sce_id][0], A[sce_id][0], lsp_new[sce_id][0], currFlatness[0], 0, fr_bands, Etot_LR, lf_E, localVAD_HE_SAD, NULL, 0, 0, 0, 0,
                                      st_ivas->hEncoderConfig->ivas_total_brate, st_ivas->hEncoderConfig->ivas_format );
+#endif
         if ( error != IVAS_ERR_OK )
         {
             return error;
diff --git a/lib_enc/ivas_sce_enc.c b/lib_enc/ivas_sce_enc.c
index 0134efc0f096a851b04d818afa0c72544872f40e..a3efe9ac7622acc3d7bc64970d03719cb334ca5d 100644
--- a/lib_enc/ivas_sce_enc.c
+++ b/lib_enc/ivas_sce_enc.c
@@ -180,12 +180,21 @@ ivas_error ivas_sce_enc(
      * Front Pre-processing
      *----------------------------------------------------------------*/
 
+#ifdef LOW_RATE_TRANS_CORE_CODER
+    error = pre_proc_front_ivas( hSCE, NULL, hSCE->element_brate, nb_bits_metadata, input_frame, 0, old_inp_12k8[0], old_inp_16k[0],
+                                 &ener[0], &relE[0], A[0], Aw[0], epsP[0], lsp_new[0], lsp_mid[0],
+                                 &vad_hover_flag[0], &attack_flag[0], realBuffer[0], imagBuffer[0], old_wsp[0], pitch_fr[0], voicing_fr[0], &loc_harm[0], &cor_map_sum[0], &vad_flag_dtx[0], enerBuffer[0],
+                                 fft_buff[0], A[0], lsp_new[0], currFlatness[0], 0, fr_bands, Etot_LR, lf_E, localVAD_HE_SAD, NULL, flag_16k_smc,
+                                 st_ivas->hSpar != NULL ? st_ivas->hSpar->front_vad_flag : 0, st_ivas->hSpar != NULL ? st_ivas->hSpar->force_front_vad : 0, st_ivas->hSpar != NULL ? st_ivas->hSpar->front_vad_dtx_flag : 0,
+                                 st_ivas->hEncoderConfig->ivas_total_brate );
+#else
     error = pre_proc_front_ivas( hSCE, NULL, hSCE->element_brate, nb_bits_metadata, input_frame, 0, old_inp_12k8[0], old_inp_16k[0],
                                  &ener[0], &relE[0], A[0], Aw[0], epsP[0], lsp_new[0], lsp_mid[0],
                                  &vad_hover_flag[0], &attack_flag[0], realBuffer[0], imagBuffer[0], old_wsp[0], pitch_fr[0], voicing_fr[0], &loc_harm[0], &cor_map_sum[0], &vad_flag_dtx[0], enerBuffer[0],
                                  fft_buff[0], A[0], lsp_new[0], currFlatness[0], 0, fr_bands, Etot_LR, lf_E, localVAD_HE_SAD, NULL, flag_16k_smc,
                                  st_ivas->hSpar != NULL ? st_ivas->hSpar->front_vad_flag : 0, st_ivas->hSpar != NULL ? st_ivas->hSpar->force_front_vad : 0, st_ivas->hSpar != NULL ? st_ivas->hSpar->front_vad_dtx_flag : 0,
                                  st_ivas->hEncoderConfig->ivas_total_brate, st_ivas->hEncoderConfig->ivas_format );
+#endif
     if ( error != IVAS_ERR_OK )
     {
         return error;
@@ -251,6 +260,11 @@ ivas_error ivas_sce_enc(
 
     hSCE->last_element_brate = hSCE->element_brate;
 
+#ifdef LOW_RATE_TRANS_CORE_CODER
+    /* Store previous attack detection flag */
+    st->hTranDet->transientDetector.prev_bIsAttackPresent = st->hTranDet->transientDetector.bIsAttackPresent;
+#endif
+
 #ifdef DEBUG_MODE_INFO
     {
         float tmpF = hSCE->element_brate / 1000.0f;