diff --git a/lib_com/options.h b/lib_com/options.h
index 4a8f7d3216b51408a7977fe6497cc240c60a706b..54347c8f135043e28fa3098f7c18f2610f4bdda4 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -190,6 +190,8 @@
 #define FIX_956_DECODER_COMMAND_LINE_FIX                /* VA: Output correct error message when the decoder command-line has too many mandatory arguments. */
 #define FIX_955_FASTCONV_REND_IN_ISM                    /* VA: put FastConv rendering call under DEBUGGING */
 #define FIX_958_667_DISABLE_INITIAL_PLC_SUPPRESSION     /* Ericsson: Fix related to issue 667 in IVAS BASOP. Handling of initial lost frame in IVAS causes non-BE on EVS BASOP 26.444 */
+#define NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX      /* FhG : issue #968: differences between 5ms and 20ms rendering for discrete ISM with BRIR and head rotation*/
+
 
 /* #################### End BASOP porting switches ############################ */
 
diff --git a/lib_dec/ivas_ism_renderer.c b/lib_dec/ivas_ism_renderer.c
index e60e17608ece168e1d3a03464f0762391dfe0d0c..5e01f7e4c468a43a49a0ab2e17ee7ff7b56315e9 100644
--- a/lib_dec/ivas_ism_renderer.c
+++ b/lib_dec/ivas_ism_renderer.c
@@ -154,6 +154,24 @@ void ivas_ism_render_sf(
     float gain, prev_gain;
     float tc_local[MAX_NUM_OBJECTS][L_FRAME48k];
     float *p_tc[MAX_NUM_OBJECTS];
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+    int16_t ism_md_subframe_update_jbm, slots_to_render, first_sf, last_sf, subframe_idx;
+    int16_t n_samples_rendered_loop;
+#endif
+
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+    /* loop for synthesis, assume we always have to render in multiples of 5ms subframes with spills */
+    slots_to_render = min( st_ivas->hTcBuffer->num_slots - st_ivas->hTcBuffer->slots_rendered, n_samples_to_render / st_ivas->hTcBuffer->n_samples_granularity );
+    first_sf = st_ivas->hTcBuffer->subframes_rendered;
+    last_sf = first_sf;
+    n_samples_rendered_loop = 0;
+
+    while ( slots_to_render > 0 )
+    {
+        slots_to_render -= st_ivas->hTcBuffer->subframe_nbslots[last_sf];
+        last_sf++;
+    }
+#endif
 
     num_objects = st_ivas->nchan_transport;
     if ( st_ivas->ivas_format == SBA_ISM_FORMAT )
@@ -166,6 +184,18 @@ void ivas_ism_render_sf(
     tc_offset = st_ivas->hTcBuffer->n_samples_rendered;
     interp_offset = st_ivas->hTcBuffer->n_samples_rendered;
 
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+    /* Number of subframes to delay metadata to sync with audio */
+    if ( st_ivas->hDecoderConfig->Opt_delay_comp )
+    {
+        ism_md_subframe_update_jbm = max( 0, st_ivas->hTcBuffer->nb_subframes - 3 );
+    }
+    else
+    {
+        ism_md_subframe_update_jbm = st_ivas->hTcBuffer->nb_subframes - 2;
+    }
+#endif
+
     if ( st_ivas->hDecoderConfig->Opt_tsm )
     {
         for ( i = 0; i < num_objects; i++ )
@@ -187,56 +217,105 @@ void ivas_ism_render_sf(
         set_f( output_f[i], 0.0f, n_samples_to_render );
     }
 
-    if ( st_ivas->hCombinedOrientationData && st_ivas->hCombinedOrientationData->enableCombinedOrientation[st_ivas->hCombinedOrientationData->subframe_idx] == 1 )
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+    for ( subframe_idx = first_sf; subframe_idx < last_sf; subframe_idx++ )
     {
-        ivas_jbm_dec_get_adapted_linear_interpolator( n_samples_to_render, n_samples_to_render, st_ivas->hIsmRendererData->interpolator );
-        interp_offset = 0;
-    }
+        int16_t n_samples_in_subframe;
 
-    for ( i = 0; i < num_objects; i++ )
-    {
-        /* Combined rotation: rotate the object positions depending the head and external orientations */
-        if ( st_ivas->hCombinedOrientationData != NULL && st_ivas->hCombinedOrientationData->enableCombinedOrientation[st_ivas->hCombinedOrientationData->subframe_idx] == 1 )
-        {
-            rotateAziEle( st_ivas->hIsmMetaData[i]->azimuth, st_ivas->hIsmMetaData[i]->elevation, &azimuth, &elevation, st_ivas->hCombinedOrientationData->Rmat[0], st_ivas->hIntSetup.is_planar_setup );
+        n_samples_in_subframe = st_ivas->hTcBuffer->n_samples_granularity * st_ivas->hTcBuffer->subframe_nbslots[subframe_idx];
+#endif
 
-            if ( st_ivas->hEFAPdata != NULL )
-            {
-                efap_determine_gains( st_ivas->hEFAPdata, st_ivas->hIsmRendererData->gains[i], azimuth, elevation, EFAP_MODE_EFAP );
-            }
+        if ( st_ivas->hCombinedOrientationData && st_ivas->hCombinedOrientationData->enableCombinedOrientation[st_ivas->hCombinedOrientationData->subframe_idx] == 1 )
+        {
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+            ivas_jbm_dec_get_adapted_linear_interpolator( n_samples_in_subframe, n_samples_in_subframe, st_ivas->hIsmRendererData->interpolator );
+#else
+        ivas_jbm_dec_get_adapted_linear_interpolator( n_samples_to_render, n_samples_to_render, st_ivas->hIsmRendererData->interpolator );
+#endif
+            interp_offset = 0;
         }
 
-        lfe_index = 0;
-        for ( j = 0, j2 = 0; j < nchan_out_woLFE; j++, j2++ )
+        for ( i = 0; i < num_objects; i++ )
         {
-            if ( ( st_ivas->hIntSetup.num_lfe > 0 ) && ( st_ivas->hIntSetup.index_lfe[lfe_index] == j ) )
+            /* Combined rotation: rotate the object positions depending the head and external orientations */
+            if ( st_ivas->hCombinedOrientationData != NULL && st_ivas->hCombinedOrientationData->enableCombinedOrientation[st_ivas->hCombinedOrientationData->subframe_idx] == 1 )
             {
-                ( lfe_index < ( st_ivas->hIntSetup.num_lfe - 1 ) ) ? ( lfe_index++, j2++ ) : j2++;
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+                if ( subframe_idx >= ism_md_subframe_update_jbm )
+                {
+                    rotateAziEle( st_ivas->hIsmMetaData[i]->azimuth, st_ivas->hIsmMetaData[i]->elevation, &azimuth, &elevation, st_ivas->hCombinedOrientationData->Rmat[st_ivas->hCombinedOrientationData->subframe_idx], st_ivas->hIntSetup.is_planar_setup );
+                }
+                else
+                {
+                    rotateAziEle( st_ivas->hIsmMetaData[i]->last_azimuth, st_ivas->hIsmMetaData[i]->last_elevation, &azimuth, &elevation, st_ivas->hCombinedOrientationData->Rmat[st_ivas->hCombinedOrientationData->subframe_idx], st_ivas->hIntSetup.is_planar_setup );
+                }
+#else
+            rotateAziEle( st_ivas->hIsmMetaData[i]->azimuth, st_ivas->hIsmMetaData[i]->elevation, &azimuth, &elevation, st_ivas->hCombinedOrientationData->Rmat[0], st_ivas->hIntSetup.is_planar_setup );
+#endif
+                if ( st_ivas->hEFAPdata != NULL )
+                {
+                    efap_determine_gains( st_ivas->hEFAPdata, st_ivas->hIsmRendererData->gains[i], azimuth, elevation, EFAP_MODE_EFAP );
+                }
             }
 
-            gain = st_ivas->hIsmRendererData->gains[i][j];
-            prev_gain = st_ivas->hIsmRendererData->prev_gains[i][j];
-            if ( fabsf( gain ) > 0.0f || fabsf( prev_gain ) > 0.0f )
+            lfe_index = 0;
+            for ( j = 0, j2 = 0; j < nchan_out_woLFE; j++, j2++ )
             {
-                g1 = &st_ivas->hIsmRendererData->interpolator[interp_offset];
-                tc = p_tc[i];
-                for ( k = 0; k < n_samples_to_render; k++ )
+                if ( ( st_ivas->hIntSetup.num_lfe > 0 ) && ( st_ivas->hIntSetup.index_lfe[lfe_index] == j ) )
+                {
+                    ( lfe_index < ( st_ivas->hIntSetup.num_lfe - 1 ) ) ? ( lfe_index++, j2++ ) : j2++;
+                }
+
+                gain = st_ivas->hIsmRendererData->gains[i][j];
+                prev_gain = st_ivas->hIsmRendererData->prev_gains[i][j];
+                if ( fabsf( gain ) > 0.0f || fabsf( prev_gain ) > 0.0f )
                 {
-                    g2 = 1.0f - *g1;
+                    g1 = &st_ivas->hIsmRendererData->interpolator[interp_offset];
+                    tc = p_tc[i];
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+                    for ( k = 0; k < n_samples_in_subframe; k++ )
+#else
+                for ( k = 0; k < n_samples_to_render; k++ )
+#endif
+                    {
+                        g2 = 1.0f - *g1;
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+                        output_f[j2][k + n_samples_rendered_loop] += ( *( g1++ ) * gain + g2 * prev_gain ) * *( tc++ );
+#else
                     output_f[j2][k] += ( *( g1++ ) * gain + g2 * prev_gain ) * *( tc++ );
+#endif
+                    }
                 }
-            }
 
-            /* update here only in case of head rotation */
-            if ( st_ivas->hCombinedOrientationData != NULL && st_ivas->hCombinedOrientationData->enableCombinedOrientation[st_ivas->hCombinedOrientationData->subframe_idx] == 1 )
-            {
-                st_ivas->hIsmRendererData->prev_gains[i][j] = gain;
+                /* update here only in case of head rotation */
+                if ( st_ivas->hCombinedOrientationData != NULL && st_ivas->hCombinedOrientationData->enableCombinedOrientation[st_ivas->hCombinedOrientationData->subframe_idx] == 1 )
+                {
+                    st_ivas->hIsmRendererData->prev_gains[i][j] = gain;
+                }
             }
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+            p_tc[i] += n_samples_in_subframe;
+#endif
         }
-    }
 
-    /* update combined orientation access index */
+        /* update combined orientation access index */
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+        ivas_combined_orientation_update_index( st_ivas->hCombinedOrientationData, n_samples_in_subframe );
+#else
     ivas_combined_orientation_update_index( st_ivas->hCombinedOrientationData, n_samples_to_render );
+#endif
+
+#ifdef NONBE_FIX_968_ISM_BRIR_WITH_HEADROTATION_5MS_FIX
+        n_samples_rendered_loop += n_samples_in_subframe;
+        if ( st_ivas->renderer_type == RENDERER_TD_PANNING )
+        {
+            st_ivas->hTcBuffer->subframes_rendered += 1;
+            st_ivas->hTcBuffer->slots_rendered += st_ivas->hTcBuffer->subframe_nbslots[subframe_idx];
+        }
+        tc_offset += n_samples_in_subframe;
+        interp_offset += n_samples_in_subframe;
+    }
+#endif
 
     return;
 }