diff --git a/lib_com/ivas_prot.h b/lib_com/ivas_prot.h
index da1f94daed5a69eaa5f80a59373a24e12a5611e9..10d35eab496e8108ad45c19810a012bdb07bf12a 100755
--- a/lib_com/ivas_prot.h
+++ b/lib_com/ivas_prot.h
@@ -5784,7 +5784,11 @@ void ivas_omasa_combine_separate_ism_with_masa(
     const int16_t output_frame                                  /* i  : output frame length per channel        */
 );
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+ivas_error ivas_omasa_objects_delay_open(
+#else
 ivas_error ivas_omasa_render_objects_from_mix_open(
+#endif
     Decoder_Struct *st_ivas                                     /* i/o: IVAS decoder structure                 */
 );
 
diff --git a/lib_com/options.h b/lib_com/options.h
index f76010a86c55f525f6fd7172cbfdb5f00c6516b4..02e3d0df8e53062fa6dcfc4d5a60c875cbd5c4f2 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -182,6 +182,7 @@
 #define FIX_1158_FASTCONV_REVERB_HRTF                   /* Philips: issue 1158: Rendering with FastConv to BINAURAL_ROOM_REVERB uses BRIR convolution instead of HRTF */
 #define FIX_1166_TDREND_DIV0                            /* FhG,Eri: issue 1166: potential divide by zero in TD Renderer */
 #define FIX_835_PARAMMC_BUFFER_VALUES                   /* FhG: BASOP issue 835: wide range of buffer values for cx in ParamMC */
+#define FIX_1161_REDUCE_OMASA_HEAP                      /* VA: reduction of OMASA heap memory */
 
 /* #################### End BE switches ################################## */
 
diff --git a/lib_dec/ivas_init_dec.c b/lib_dec/ivas_init_dec.c
index 3930c3b2c1ce17a8fde3c3b81fce7a620cc517c5..edd3ed644e8f3425cacc207c792fe5ff5bedb4b1 100644
--- a/lib_dec/ivas_init_dec.c
+++ b/lib_dec/ivas_init_dec.c
@@ -1898,17 +1898,31 @@ ivas_error ivas_init_decoder(
                 }
             }
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+            /* Allocate memory for delay buffer within 'hMasaIsmData' */
+            if ( ( error = ivas_omasa_objects_delay_open( st_ivas ) ) != IVAS_ERR_OK )
+            {
+                return error;
+            }
+#else
             /* Allocate 'hIsmRendererData' handle and memory for delay buffer within 'hMasaIsmData' */
             if ( ( error = ivas_omasa_separate_object_renderer_open( st_ivas ) ) != IVAS_ERR_OK )
             {
                 return error;
             }
+#endif
         }
 
         if ( ( st_ivas->renderer_type == RENDERER_DIRAC ) &&
              ( st_ivas->ism_mode == ISM_MASA_MODE_MASA_ONE_OBJ || st_ivas->ism_mode == ISM_MASA_MODE_PARAM_ONE_OBJ || st_ivas->ism_mode == ISM_MASA_MODE_DISC ) )
         {
             /* Allocate 'hIsmRendererData' handle and memory for delay buffer within 'hMasaIsmData' */
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+            if ( ( error = ivas_omasa_objects_delay_open( st_ivas ) ) != IVAS_ERR_OK )
+            {
+                return error;
+            }
+#endif
             if ( ( error = ivas_omasa_separate_object_renderer_open( st_ivas ) ) != IVAS_ERR_OK )
             {
                 return error;
@@ -1918,7 +1932,11 @@ ivas_error ivas_init_decoder(
         if ( st_ivas->renderer_type == RENDERER_OMASA_OBJECT_EXT )
         {
             /* Allocate 'hIsmRendererData' handle and memory for delay buffer within 'hMasaIsmData' */
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+            if ( ( error = ivas_omasa_objects_delay_open( st_ivas ) ) != IVAS_ERR_OK )
+#else
             if ( ( error = ivas_omasa_render_objects_from_mix_open( st_ivas ) ) != IVAS_ERR_OK )
+#endif
             {
                 return error;
             }
diff --git a/lib_dec/ivas_ism_renderer.c b/lib_dec/ivas_ism_renderer.c
index ae6e4523137882bfa65a821847b20815ce7c2530..daefbfbdccb484dec6dcabcccc5406385853a294 100644
--- a/lib_dec/ivas_ism_renderer.c
+++ b/lib_dec/ivas_ism_renderer.c
@@ -354,7 +354,7 @@ void ivas_ism_get_stereo_gains(
 
 
 /*-------------------------------------------------------------------------*
- * ivas_masa_oism_separate_object_renderer_open()
+ * ivas_omasa_separate_object_renderer_open()
  *
  * Open structures, reserve memory, and init values.
  *-------------------------------------------------------------------------*/
@@ -379,7 +379,14 @@ ivas_error ivas_omasa_separate_object_renderer_open(
 
     init_interpolator_length = (int16_t) ( st_ivas->hDecoderConfig->output_Fs / FRAMES_PER_SEC / MAX_PARAM_SPATIAL_SUBFRAMES );
     interpolator_length = init_interpolator_length;
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    if ( ( st_ivas->hIsmRendererData->interpolator = (float *) malloc( sizeof( float ) * init_interpolator_length ) ) == NULL )
+    {
+        return ( IVAS_ERROR( IVAS_ERR_FAILED_ALLOC, "Cannot allocate memory for MASA ISM renderer interpolator \n" ) );
+    }
+#else
     st_ivas->hIsmRendererData->interpolator = (float *) malloc( sizeof( float ) * init_interpolator_length );
+#endif
 
     for ( i = 0; i < interpolator_length; i++ )
     {
@@ -387,6 +394,7 @@ ivas_error ivas_omasa_separate_object_renderer_open(
     }
     st_ivas->hIsmRendererData->interpolator_length = interpolator_length;
 
+#ifndef FIX_1161_REDUCE_OMASA_HEAP
     st_ivas->hMasaIsmData->delayBuffer_size = (int16_t) ( ( st_ivas->hDecoderConfig->output_Fs / 50 ) / MAX_PARAM_SPATIAL_SUBFRAMES );
 
     if ( st_ivas->ism_mode == ISM_MASA_MODE_MASA_ONE_OBJ || st_ivas->ism_mode == ISM_MASA_MODE_PARAM_ONE_OBJ )
@@ -412,6 +420,7 @@ ivas_error ivas_omasa_separate_object_renderer_open(
         set_zero( st_ivas->hMasaIsmData->delayBuffer[i], st_ivas->hMasaIsmData->delayBuffer_size );
     }
 
+#endif
     return IVAS_ERR_OK;
 }
 
diff --git a/lib_dec/ivas_masa_dec.c b/lib_dec/ivas_masa_dec.c
index 436517639dd6c8ae14c11e8cacda9395099caae8..c18369d1f675d18e8eb762e61f1e2db7ed5befb7 100644
--- a/lib_dec/ivas_masa_dec.c
+++ b/lib_dec/ivas_masa_dec.c
@@ -869,7 +869,11 @@ static ivas_error ivas_masa_dec_config(
     for ( i = 0; i < st_ivas->hQMetaData->no_directions; i++ )
     {
         st_ivas->hQMetaData->q_direction[i].cfg.nbands = hMasa->config.numCodingBands;
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+        st_ivas->hQMetaData->q_direction[i].cfg.nblocks = hMasa->config.joinedSubframes == TRUE ? 1 : MAX_PARAM_SPATIAL_SUBFRAMES;
+#else
         st_ivas->hQMetaData->q_direction[i].cfg.nblocks = hMasa->config.joinedSubframes == TRUE ? 1 : 4;
+#endif
 
         if ( st_ivas->ivas_format == MC_FORMAT && st_ivas->mc_mode == MC_MODE_MCMASA )
         {
diff --git a/lib_dec/ivas_omasa_dec.c b/lib_dec/ivas_omasa_dec.c
index 8164c2aa656d8a5c586ebdc4cc0ea77ddf71f3c2..c38f9bc174b1c29eb3687224815f76b760cc68ae 100644
--- a/lib_dec/ivas_omasa_dec.c
+++ b/lib_dec/ivas_omasa_dec.c
@@ -445,11 +445,19 @@ ivas_error ivas_omasa_dec_config(
                     }
                 }
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                /* Allocate memory for delay buffer within 'hMasaIsmData' */
+                if ( ( error = ivas_omasa_objects_delay_open( st_ivas ) ) != IVAS_ERR_OK )
+                {
+                    return error;
+                }
+#else
                 /* Allocate 'hIsmRendererData' handle and memory for delay buffer within 'hMasaIsmData' */
                 if ( ( error = ivas_omasa_separate_object_renderer_open( st_ivas ) ) != IVAS_ERR_OK )
                 {
                     return error;
                 }
+#endif
             }
             else
             {
@@ -473,6 +481,12 @@ ivas_error ivas_omasa_dec_config(
             if ( st_ivas->ism_mode == ISM_MASA_MODE_MASA_ONE_OBJ || st_ivas->ism_mode == ISM_MASA_MODE_PARAM_ONE_OBJ || st_ivas->ism_mode == ISM_MASA_MODE_DISC )
             {
                 /* Allocate 'hIsmRendererData' handle and memory for delay buffer within 'hMasaIsmData' */
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                if ( ( error = ivas_omasa_objects_delay_open( st_ivas ) ) != IVAS_ERR_OK )
+                {
+                    return error;
+                }
+#endif
                 if ( ( error = ivas_omasa_separate_object_renderer_open( st_ivas ) ) != IVAS_ERR_OK )
                 {
                     return error;
@@ -499,7 +513,11 @@ ivas_error ivas_omasa_dec_config(
             DIRAC_CONFIG_FLAG common_rend_config_flag = st_ivas->hSpatParamRendCom == NULL ? DIRAC_OPEN : DIRAC_RECONFIGURE;
 
             /* Allocate 'hIsmRendererData' handle and memory for delay buffer within 'hMasaIsmData' */
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+            if ( ( error = ivas_omasa_objects_delay_open( st_ivas ) ) != IVAS_ERR_OK )
+#else
             if ( ( error = ivas_omasa_render_objects_from_mix_open( st_ivas ) ) != IVAS_ERR_OK )
+#endif
             {
                 return error;
             }
@@ -1102,6 +1120,15 @@ void ivas_omasa_combine_separate_ism_with_masa(
 }
 
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+/*-------------------------------------------------------------------------*
+ * ivas_omasa_objects_delay_open()
+ *
+ * Open structures, reserve memory, and init values for dela buffers of objects.
+ *-------------------------------------------------------------------------*/
+
+ivas_error ivas_omasa_objects_delay_open(
+#else
 /*-------------------------------------------------------------------------*
  * ivas_omasa_render_objects_from_mix_open()
  *
@@ -1109,12 +1136,24 @@ void ivas_omasa_combine_separate_ism_with_masa(
  *-------------------------------------------------------------------------*/
 
 ivas_error ivas_omasa_render_objects_from_mix_open(
+#endif
     Decoder_Struct *st_ivas /* i/o: IVAS decoder structure */
 )
 {
     int16_t i;
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    if ( st_ivas->ism_mode == ISM_MASA_MODE_MASA_ONE_OBJ || st_ivas->ism_mode == ISM_MASA_MODE_PARAM_ONE_OBJ )
+    {
+        st_ivas->hMasaIsmData->delayBuffer_nchan = 1;
+    }
+    else
+    {
+        st_ivas->hMasaIsmData->delayBuffer_nchan = st_ivas->nchan_ism;
+    }
+#else
     st_ivas->hMasaIsmData->delayBuffer_nchan = 1;
+#endif
 
     st_ivas->hMasaIsmData->delayBuffer_size = (int16_t) ( ( st_ivas->hDecoderConfig->output_Fs / 50 ) / MAX_PARAM_SPATIAL_SUBFRAMES );
 
diff --git a/lib_enc/ivas_masa_enc.c b/lib_enc/ivas_masa_enc.c
index 54691e864e63e6cc5b2af98591b2616953961814..480838848f6907a2bce6879f027239437d37c114 100644
--- a/lib_enc/ivas_masa_enc.c
+++ b/lib_enc/ivas_masa_enc.c
@@ -174,6 +174,20 @@ ivas_error ivas_masa_enc_open(
         hOmasaData->lp_noise_CPE = -1;
         hOmasaData->omasa_stereo_sw_cnt = OMASA_STEREO_SW_CNT_MAX;
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+        if ( st_ivas->ism_mode != ISM_MASA_MODE_DISC )
+        {
+            if ( ( hOmasaData->hOmasaEnergy = (OMASA_ENCODER_ENERGY_HANDLE) malloc( sizeof( OMASA_ENCODER_ENERGY_STATE ) ) ) == NULL )
+            {
+                return ( IVAS_ERROR( IVAS_ERR_FAILED_ALLOC, "Can not allocate memory for OMASA energy handle\n" ) );
+            }
+        }
+        else
+        {
+            hOmasaData->hOmasaEnergy = NULL;
+        }
+#endif
+
         hMasa->data.hOmasaData = hOmasaData;
     }
     else
@@ -211,6 +225,14 @@ void ivas_masa_enc_close(
 
     if ( ( *hMasa )->data.hOmasaData != NULL )
     {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+        if ( ( *hMasa )->data.hOmasaData->hOmasaEnergy != NULL )
+        {
+            free( ( *hMasa )->data.hOmasaData->hOmasaEnergy );
+            ( *hMasa )->data.hOmasaData->hOmasaEnergy = NULL;
+        }
+
+#endif
         free( ( *hMasa )->data.hOmasaData );
         ( *hMasa )->data.hOmasaData = NULL;
     }
@@ -816,7 +838,11 @@ ivas_error ivas_masa_enc_config(
     for ( i = 0; i < hQMetaData->no_directions; i++ )
     {
         hQMetaData->q_direction[i].cfg.nbands = hMasa->config.numCodingBands;
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+        hQMetaData->q_direction[i].cfg.nblocks = hMasa->config.joinedSubframes == TRUE ? 1 : MAX_PARAM_SPATIAL_SUBFRAMES;
+#else
         hQMetaData->q_direction[i].cfg.nblocks = hMasa->config.joinedSubframes == TRUE ? 1 : 4;
+#endif
 
         if ( ivas_format == MC_FORMAT )
         {
@@ -1329,7 +1355,11 @@ static void move_metadata_to_qmetadata(
 
     numCodingBands = hMasa->config.numCodingBands;
     numDirections = hMasa->config.numberOfDirections;
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    numSf = hMasa->config.joinedSubframes == TRUE ? 1 : MAX_PARAM_SPATIAL_SUBFRAMES;
+#else
     numSf = hMasa->config.joinedSubframes == TRUE ? 1 : 4;
+#endif
     hMeta = &( hMasa->masaMetadata );
 
     for ( dir = 0; dir < numDirections; dir++ )
@@ -2621,10 +2651,17 @@ void ivas_merge_masa_metadata(
     float total_diff_nrg;
     float eneBand;
     float energyMerged[MAX_PARAM_SPATIAL_SUBFRAMES][MASA_FREQUENCY_BANDS];
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    OMASA_ENCODER_ENERGY_HANDLE hOmasaEnergy = hMasa->data.hOmasaData->hOmasaEnergy;
+#endif
 
     numCodingBands = hMasa->config.numCodingBands;
     numDirections = hMasa->config.numberOfDirections;
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    numSf = hMasa->config.joinedSubframes == TRUE ? 1 : MAX_PARAM_SPATIAL_SUBFRAMES;
+#else
     numSf = hMasa->config.joinedSubframes == TRUE ? 1 : 4;
+#endif
     hMeta = &( hMasa->masaMetadata );
 
     for ( sf = 0; sf < numSf; sf++ )
@@ -2645,7 +2682,11 @@ void ivas_merge_masa_metadata(
 
             /* Compute energies */
             eneBand = hMasa->data.energy[sf][band];
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+            energyMerged[sf][band] = eneBand + hOmasaEnergy->energy_ism[sf][band];
+#else
             energyMerged[sf][band] = eneBand + hMasa->data.hOmasaData->energy_ism[sf][band];
+#endif
 
             /* Compute weights */
             energyTimesRatioMASA[0] = eneBand * hMeta->directional_meta[0].energy_ratio[sf][band];
@@ -2662,7 +2703,11 @@ void ivas_merge_masa_metadata(
             total_diff_nrg = eneBand * hMeta->common_meta.diffuse_to_total_ratio[sf][band];
 
             /* criterion is mean of ISM ratio and new ratio */
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+            energyTimesRatioISM = ( hOMasaMeta->directional_meta[0].energy_ratio[sf][band] + ( 1.0f - total_diff_nrg / ( EPSILON + eneBand + hOmasaEnergy->energy_ism[sf][band] ) ) ) / 2.0f * hMasa->data.hOmasaData->hOmasaEnergy->energy_ism[sf][band];
+#else
             energyTimesRatioISM = ( hOMasaMeta->directional_meta[0].energy_ratio[sf][band] + ( 1.0f - total_diff_nrg / ( EPSILON + eneBand + hMasa->data.hOmasaData->energy_ism[sf][band] ) ) ) / 2.0f * hMasa->data.hOmasaData->energy_ism[sf][band];
+#endif
 
             /* Determine combined metadata based on the weights */
             merge_dest = -1;
@@ -2682,8 +2727,13 @@ void ivas_merge_masa_metadata(
             {
                 hMeta->directional_meta[merge_dest].azimuth[sf][band] = hOMasaMeta->directional_meta[0].azimuth[sf][band];
                 hMeta->directional_meta[merge_dest].elevation[sf][band] = hOMasaMeta->directional_meta[0].elevation[sf][band];
+
                 /* limit with the earlier direct-energy ratio */
-                dir_sum = 1.0f - total_diff_nrg / ( EPSILON + eneBand + hMasa->data.hOmasaData->energy_ism[sf][band] );                              /* new dir ratio */
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                dir_sum = 1.0f - total_diff_nrg / ( EPSILON + eneBand + hOmasaEnergy->energy_ism[sf][band] ); /* new dir ratio */
+#else
+                dir_sum = 1.0f - total_diff_nrg / ( EPSILON + eneBand + hMasa->data.hOmasaData->energy_ism[sf][band] ); /* new dir ratio */
+#endif
                 hMeta->directional_meta[merge_dest].energy_ratio[sf][band] = min( dir_sum, hOMasaMeta->directional_meta[0].energy_ratio[sf][band] ); /* clip with original ISM dir */
                 hMeta->common_meta.diffuse_to_total_ratio[sf][band] = 1.0f - hMeta->directional_meta[merge_dest].energy_ratio[sf][band];
 
@@ -3398,6 +3448,9 @@ static void ivas_encode_masaism_metadata(
     int16_t tmp, rotate;
     int16_t n_ism_tmp, i;
     OMASA_ENCODER_DATA_HANDLE hOmasaData = hMasa->data.hOmasaData;
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    OMASA_ENCODER_ENERGY_HANDLE hOmasaEnergy = hOmasaData->hOmasaEnergy;
+#endif
     int16_t nbands_work;
 
     /* use the values from hQMetaData */
@@ -3408,7 +3461,11 @@ static void ivas_encode_masaism_metadata(
     {
         for ( sf = 0; sf < numSf; sf++ )
         {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+            if ( sum_f( hOmasaEnergy->energy_ism[sf], omasa_nbands ) == 0.0f )
+#else
             if ( sum_f( hOmasaData->energy_ism[sf], omasa_nbands ) == 0.0f )
+#endif
             {
                 hOmasaData->masa_to_total_energy_ratio[sf][0] = 1.0f;
             }
@@ -3430,16 +3487,28 @@ static void ivas_encode_masaism_metadata(
 
                 for ( band = 0; band < omasa_nbands; band++ )
                 {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                    energy_ism += hOmasaEnergy->energy_ism[sf][band];
+#else
                     energy_ism += hOmasaData->energy_ism[sf][band];
+#endif
                     for ( obj = 0; obj < nchan_ism; obj++ )
                     {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                        energy_ism_ind[obj] += hOmasaEnergy->energy_ism[sf][band] * hOmasaEnergy->energy_ratio_ism[sf][band][obj];
+#else
                         energy_ism_ind[obj] += hOmasaData->energy_ism[sf][band] * hOmasaData->energy_ratio_ism[sf][band][obj];
+#endif
                     }
                 }
 
                 for ( obj = 0; obj < nchan_ism; obj++ )
                 {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                    hOmasaEnergy->energy_ratio_ism[sf][0][obj] = energy_ism_ind[obj] / energy_ism;
+#else
                     hOmasaData->energy_ratio_ism[sf][0][obj] = energy_ism_ind[obj] / energy_ism;
+#endif
                 }
                 hOmasaData->masa_to_total_energy_ratio[sf][0] = eneBand / ( eneBand + energy_ism + EPSILON );
             }
@@ -3456,10 +3525,18 @@ static void ivas_encode_masaism_metadata(
             }
             for ( sf = 0; sf < omasa_nblocks; sf++ )
             {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                energy_ism += hOmasaEnergy->energy_ism[sf][band];
+#else
                 energy_ism += hOmasaData->energy_ism[sf][band];
+#endif
                 for ( obj = 0; obj < nchan_ism; obj++ )
                 {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                    energy_ism_ind[obj] += hOmasaEnergy->energy_ism[sf][band] * hOmasaEnergy->energy_ratio_ism[sf][band][obj];
+#else
                     energy_ism_ind[obj] += hOmasaData->energy_ism[sf][band] * hOmasaData->energy_ratio_ism[sf][band][obj];
+#endif
                 }
             }
 
@@ -3471,7 +3548,11 @@ static void ivas_encode_masaism_metadata(
             {
                 for ( obj = 0; obj < nchan_ism; obj++ )
                 {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                    hOmasaEnergy->energy_ratio_ism[0][band][obj] = energy_ism_ind[obj] / energy_ism;
+#else
                     hOmasaData->energy_ratio_ism[0][band][obj] = energy_ism_ind[obj] / energy_ism;
+#endif
                 }
                 brange[0] = hMasa->data.band_mapping[band];
                 brange[1] = hMasa->data.band_mapping[band + 1];
@@ -3493,7 +3574,11 @@ static void ivas_encode_masaism_metadata(
 
             for ( obj = 0; obj < nchan_ism; obj++ )
             {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                hOmasaEnergy->energy_ratio_ism[0][band][obj] = hOmasaEnergy->energy_ratio_ism[0][nbands_work - 1][obj];
+#else
                 hOmasaData->energy_ratio_ism[0][band][obj] = hOmasaData->energy_ratio_ism[0][nbands_work - 1][obj];
+#endif
             }
         }
     }
@@ -3503,7 +3588,11 @@ static void ivas_encode_masaism_metadata(
         {
             for ( band = 0; band < nbands_work; band++ )
             {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                if ( hOmasaEnergy->energy_ism[sf][band] == 0.0f )
+#else
                 if ( hOmasaData->energy_ism[sf][band] == 0.0f )
+#endif
                 {
                     hOmasaData->masa_to_total_energy_ratio[sf][band] = 1.0f;
                 }
@@ -3517,7 +3606,11 @@ static void ivas_encode_masaism_metadata(
                     {
                         eneBand += hMasa->data.energy[sf][bin];
                     }
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                    hOmasaData->masa_to_total_energy_ratio[sf][band] = eneBand / ( eneBand + hOmasaEnergy->energy_ism[sf][band] + EPSILON );
+#else
                     hOmasaData->masa_to_total_energy_ratio[sf][band] = eneBand / ( eneBand + hOmasaData->energy_ism[sf][band] + EPSILON );
+#endif
                 }
             }
             for ( band = nbands_work; band < numCodingBands; band++ )
@@ -3526,7 +3619,11 @@ static void ivas_encode_masaism_metadata(
 
                 for ( obj = 0; obj < nchan_ism; obj++ )
                 {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                    hOmasaEnergy->energy_ratio_ism[sf][band][obj] = hOmasaEnergy->energy_ratio_ism[sf][nbands_work - 1][obj];
+#else
                     hOmasaData->energy_ratio_ism[sf][band][obj] = hOmasaData->energy_ratio_ism[sf][nbands_work - 1][obj];
+#endif
                 }
             }
         }
@@ -3548,8 +3645,13 @@ static void ivas_encode_masaism_metadata(
             {
                 for ( obj = 0; obj < nchan_ism; obj++ )
                 {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                    assert( ( hOmasaEnergy->energy_ratio_ism[sf][band][obj] >= 0 ) && ( hOmasaEnergy->energy_ratio_ism[sf][band][obj] <= 1 ) );
+                    ratio_ism[band][obj] = hOmasaEnergy->energy_ratio_ism[sf][band][obj];
+#else
                     assert( ( hOmasaData->energy_ratio_ism[sf][band][obj] >= 0 ) && ( hOmasaData->energy_ratio_ism[sf][band][obj] <= 1 ) );
                     ratio_ism[band][obj] = hOmasaData->energy_ratio_ism[sf][band][obj];
+#endif
                 }
 
                 /* Quantize ISM ratios */
@@ -3573,7 +3675,11 @@ static void ivas_encode_masaism_metadata(
                 }
 
                 /* reconstructed values */
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                reconstruct_ism_ratios( ratio_ism_idx[band], nchan_ism, step, hOmasaEnergy->q_energy_ratio_ism[sf][band] );
+#else
                 reconstruct_ism_ratios( ratio_ism_idx[band], nchan_ism, step, hMasa->data.hOmasaData->q_energy_ratio_ism[sf][band] );
+#endif
             }
 
             if ( ( nchan_ism > 2 ) && ( idx_separated_object == nchan_ism - 1 ) )
@@ -3648,7 +3754,11 @@ static void ivas_encode_masaism_metadata(
         }
     }
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    calculate_nbits_meta( nchan_ism, hOmasaEnergy->q_energy_ratio_ism, hOmasaData->masa_to_total_energy_ratio, numSf, numCodingBands, bits_ism, idx_separated_object, ism_imp );
+#else
     calculate_nbits_meta( nchan_ism, hOmasaData->q_energy_ratio_ism, hOmasaData->masa_to_total_energy_ratio, numSf, numCodingBands, bits_ism, idx_separated_object, ism_imp );
+#endif
 
     /* quantize directions */
     for ( obj = 0; obj < nchan_ism; obj++ )
diff --git a/lib_enc/ivas_omasa_enc.c b/lib_enc/ivas_omasa_enc.c
index b9bb5981cd6be64318e93e7693de4a5e040b75fc..4e184d59a5de505bf34f9617161b5778d101a2af 100644
--- a/lib_enc/ivas_omasa_enc.c
+++ b/lib_enc/ivas_omasa_enc.c
@@ -276,6 +276,7 @@ ivas_error ivas_omasa_enc_config(
 
         ivas_write_format( st_ivas );
 
+        /* OMASA encoder handle */
         if ( st_ivas->ism_mode != ISM_MASA_MODE_DISC && st_ivas->hOMasa == NULL )
         {
             if ( ( error = ivas_omasa_enc_open( st_ivas ) ) != IVAS_ERR_OK )
@@ -289,6 +290,22 @@ ivas_error ivas_omasa_enc_config(
             st_ivas->hOMasa = NULL;
         }
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+        /* OMASA energy handle */
+        if ( st_ivas->ism_mode != ISM_MASA_MODE_DISC && st_ivas->hMasa->data.hOmasaData->hOmasaEnergy == NULL )
+        {
+            if ( ( st_ivas->hMasa->data.hOmasaData->hOmasaEnergy = (OMASA_ENCODER_ENERGY_HANDLE) malloc( sizeof( OMASA_ENCODER_ENERGY_STATE ) ) ) == NULL )
+            {
+                return ( IVAS_ERROR( IVAS_ERR_FAILED_ALLOC, "Can not allocate memory for OMASA energy handle\n" ) );
+            }
+        }
+        else if ( st_ivas->ism_mode == ISM_MASA_MODE_DISC && st_ivas->hMasa->data.hOmasaData->hOmasaEnergy != NULL )
+        {
+            free( st_ivas->hMasa->data.hOmasaData->hOmasaEnergy );
+            st_ivas->hMasa->data.hOmasaData->hOmasaEnergy = NULL;
+        }
+
+#endif
         st_ivas->hCPE[0]->element_brate = ivas_total_brate - ism_total_brate;
 
         if ( ivas_total_brate - ism_total_brate >= MIN_BRATE_MDCT_STEREO )
@@ -822,6 +839,9 @@ static void ivas_omasa_param_est_enc(
     float renormalization_factor_diff[MASA_FREQUENCY_BANDS];
     float norm_tmp;
     int16_t mrange[2], brange[2];
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    OMASA_ENCODER_ENERGY_HANDLE hOmasaEnergy = hOmasaData->hOmasaEnergy;
+#endif
 
     num_freq_bins = hOMasa->cldfbAnaEnc[0]->no_channels;
     num_freq_bands = hOMasa->nbands;
@@ -853,7 +873,11 @@ static void ivas_omasa_param_est_enc(
             hOMasa->direction_vector_m[2][block_m_idx][band_m_idx] = 0.0f;
         }
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+        set_zero( hOmasaEnergy->energy_ism[block_m_idx], num_freq_bands );
+#else
         set_zero( hOmasaData->energy_ism[block_m_idx], num_freq_bands );
+#endif
 
         for ( ts = mrange[0]; ts < mrange[1]; ts++ )
         {
@@ -871,7 +895,11 @@ static void ivas_omasa_param_est_enc(
                 {
                     for ( k = 0; k < nchan_ism; k++ )
                     {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                        hOmasaEnergy->energy_ism[block_m_idx][i] += Chnl_RealBuffer[k][j] * Chnl_RealBuffer[k][j] + Chnl_ImagBuffer[k][j] * Chnl_ImagBuffer[k][j];
+#else
                         hOmasaData->energy_ism[block_m_idx][i] += Chnl_RealBuffer[k][j] * Chnl_RealBuffer[k][j] + Chnl_ImagBuffer[k][j] * Chnl_ImagBuffer[k][j];
+#endif
                     }
                 }
             }
@@ -999,6 +1027,9 @@ static void ivas_omasa_energy_and_ratio_est(
     int16_t mrange[2], brange[2];
     float tftile_energy;
     float ism_ratio_sum;
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    OMASA_ENCODER_ENERGY_HANDLE hOmasaEnergy = hOmasaData->hOmasaEnergy;
+#endif
 
     num_freq_bands = hOMasa->nbands;
     l_ts = input_frame / CLDFB_NO_COL_MAX;
@@ -1012,9 +1043,17 @@ static void ivas_omasa_energy_and_ratio_est(
         /* Reset variable */
         for ( i = 0; i < hOMasa->nbands; i++ )
         {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+            set_zero( hOmasaEnergy->energy_ratio_ism[block_m_idx][i], nchan_ism );
+#else
             set_zero( hOmasaData->energy_ratio_ism[block_m_idx][i], nchan_ism );
+#endif
         }
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+        set_zero( hOmasaEnergy->energy_ism[block_m_idx], num_freq_bands );
+#else
         set_zero( hOmasaData->energy_ism[block_m_idx], num_freq_bands );
+#endif
 
         /* Compute CLDFB */
         for ( ts = mrange[0]; ts < mrange[1]; ts++ )
@@ -1034,8 +1073,14 @@ static void ivas_omasa_energy_and_ratio_est(
                     for ( k = 0; k < nchan_ism; k++ )
                     {
                         tftile_energy = Chnl_RealBuffer[k][j] * Chnl_RealBuffer[k][j] + Chnl_ImagBuffer[k][j] * Chnl_ImagBuffer[k][j];
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                        hOmasaEnergy->energy_ism[block_m_idx][i] += tftile_energy;
+                        hOmasaEnergy->energy_ratio_ism[block_m_idx][i][k] += tftile_energy;
+
+#else
                         hOmasaData->energy_ism[block_m_idx][i] += tftile_energy;
                         hOmasaData->energy_ratio_ism[block_m_idx][i][k] += tftile_energy;
+#endif
                     }
                 }
             }
@@ -1047,8 +1092,13 @@ static void ivas_omasa_energy_and_ratio_est(
             ism_ratio_sum = 0.0f;
             for ( j = 0; j < nchan_ism; j++ )
             {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                hOmasaEnergy->energy_ratio_ism[block_m_idx][i][j] /= ( hOmasaEnergy->energy_ism[block_m_idx][i] + EPSILON );
+                ism_ratio_sum += hOmasaEnergy->energy_ratio_ism[block_m_idx][i][j];
+#else
                 hOmasaData->energy_ratio_ism[block_m_idx][i][j] /= ( hOmasaData->energy_ism[block_m_idx][i] + EPSILON );
                 ism_ratio_sum += hOmasaData->energy_ratio_ism[block_m_idx][i][j];
+#endif
             }
 
             if ( ism_ratio_sum == 0.0f )
@@ -1056,7 +1106,11 @@ static void ivas_omasa_energy_and_ratio_est(
                 float temp_ism_ratio = 1.0f / ( (float) nchan_ism );
                 for ( j = 0; j < nchan_ism; j++ )
                 {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+                    hOmasaEnergy->energy_ratio_ism[block_m_idx][i][j] = temp_ism_ratio;
+#else
                     hOmasaData->energy_ratio_ism[block_m_idx][i][j] = temp_ism_ratio;
+#endif
                 }
             }
         }
diff --git a/lib_enc/ivas_stat_enc.h b/lib_enc/ivas_stat_enc.h
index 3962ac055f232389b780a957c227cd5a3bd203be..f0284ff7882568f3d1242f71e0e79b0a6378447d 100644
--- a/lib_enc/ivas_stat_enc.h
+++ b/lib_enc/ivas_stat_enc.h
@@ -794,12 +794,25 @@ typedef struct ivas_omasa_enc_state_structure
 
 } OMASA_ENC_STATE, *OMASA_ENC_HANDLE;
 
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+typedef struct ivas_omasa_encoder_energy_struct
+{
+    float energy_ism[MAX_PARAM_SPATIAL_SUBFRAMES][MASA_FREQUENCY_BANDS];
+    float energy_ratio_ism[MAX_PARAM_SPATIAL_SUBFRAMES][MASA_FREQUENCY_BANDS][MAX_NUM_OBJECTS];
+    float q_energy_ratio_ism[MAX_PARAM_SPATIAL_SUBFRAMES][MASA_FREQUENCY_BANDS][MAX_NUM_OBJECTS];
 
-typedef struct ivas_omasa_encoder_one_data_struct
+} OMASA_ENCODER_ENERGY_STATE, *OMASA_ENCODER_ENERGY_HANDLE;
+
+#endif
+typedef struct ivas_omasa_encoder_data_struct
 {
+#ifdef FIX_1161_REDUCE_OMASA_HEAP
+    OMASA_ENCODER_ENERGY_HANDLE hOmasaEnergy;
+#else
     float energy_ism[MAX_PARAM_SPATIAL_SUBFRAMES][MASA_FREQUENCY_BANDS];
     float energy_ratio_ism[MAX_PARAM_SPATIAL_SUBFRAMES][MASA_FREQUENCY_BANDS][MAX_NUM_OBJECTS];
     float q_energy_ratio_ism[MAX_PARAM_SPATIAL_SUBFRAMES][MASA_FREQUENCY_BANDS][MAX_NUM_OBJECTS];
+#endif
     float masa_to_total_energy_ratio[MAX_PARAM_SPATIAL_SUBFRAMES][MASA_FREQUENCY_BANDS];
     float lp_noise_CPE; /* LP filtered total noise estimation */
     int16_t omasa_stereo_sw_cnt;