diff --git a/lib_com/options.h b/lib_com/options.h
index 633a3976b4212628f7809e50507150387fc50048..af5127066c1d70df5811d25795c3052901c2ba9e 100644
--- a/lib_com/options.h
+++ b/lib_com/options.h
@@ -104,6 +104,7 @@
 #define FIX_2010_PREP_TBE_EXC                                /* FhG: fix issues with varying Q-values for code_preQ_fx[] */
 #define FIX_2025_FDCNG_MULT                                  /* Nokia, FhG: Fix LB FDCNG noise introduced by changing mult to i_mult */
 
+#define OPT_IGF_GET_WHITE_SPEC_DATA                          /* FhG: optimized version of IGF_getWhiteSpectralData_ivas() */
 #define FIX_1962_FORMAT_CONV_SPECTRAL_DIFF                   /* FhG: Improved precision of targetEnergy in ivas_ls_setup_conversion_process_mdct_fx() */
 #define FIX_2003_CON_TCX_OVERFLOW                            /* FhG: Use a dynamic scaling factor for the synth buffer at the output of con_tcx_ivas_fx() */
 #define HP20_FIX32_RECODING                                  /* FhG: optimized hp20_fx_32 calculation and applied it as hp20_fx_32_opt in decoder */
diff --git a/lib_dec/igf_dec_fx.c b/lib_dec/igf_dec_fx.c
index ee462d7c550d1871a6ae948c118c270f310e556c..e2434ffd7d476da8015c2c3ade7d062312954d79 100644
--- a/lib_dec/igf_dec_fx.c
+++ b/lib_dec/igf_dec_fx.c
@@ -2905,6 +2905,9 @@ static void IGF_getWhiteSpectralData_ivas(
     Word16 tmp_e;
     Word16 out_e_arr[IGF_START_MX + MAX_IGF_SFB_LEN];
     Word16 max_out_e;
+#ifdef OPT_IGF_GET_WHITE_SPEC_DATA
+    Word64 window_sum;
+#endif
     assert( LT_16( stop, IGF_START_MX + MAX_IGF_SFB_LEN ) );
 
     /* inits */
@@ -2930,8 +2933,22 @@ static void IGF_getWhiteSpectralData_ivas(
     ak_e = add( tmp_e, sub( shl( sub( in_e, s_l ), 1 ), 15 ) ); // tmp_e + 2 * (in_e - s_l) - 15
     ak_e = sub( ak_e, 1 );
 
+#ifdef OPT_IGF_GET_WHITE_SPEC_DATA
+    window_sum = 0;
+    move64();
+    FOR( j = start - level; j < start + level; j++ )
+    {
+        window_sum = W_mac_32_32( window_sum, in[j], in[j] );
+    }
+#endif
+
     FOR( i = start; i < stop - level; i++ )
     {
+#ifdef OPT_IGF_GET_WHITE_SPEC_DATA
+        window_sum = W_mac_32_32( window_sum, in[i + level], in[i + level] );           /* add the right one */
+        ak = Mult_32_16( W_shl_sat_l( window_sum, shift ), quo );                       // add( shl( level, 1 ), 1 ), &tmp_e ) );
+        window_sum = W_sub( window_sum, W_mult_32_32( in[i - level], in[i - level] ) ); /* subtract the left one */
+#else
         Word64 temp = 0;
         move64();
         FOR( j = i - level; j < i + level + 1; j++ )
@@ -2939,7 +2956,7 @@ static void IGF_getWhiteSpectralData_ivas(
             temp = W_mac_32_32( temp, in[j], in[j] );
         }
         ak = Mult_32_16( W_shl_sat_l( temp, shift ), quo ); // add( shl( level, 1 ), 1 ), &tmp_e ) );
-
+#endif
 
         n = sub( ak_e, norm_l( ak ) );
         n = shr( n, 1 );
@@ -2951,6 +2968,11 @@ static void IGF_getWhiteSpectralData_ivas(
 
     FOR( ; i < stop; i++ )
     {
+#ifdef OPT_IGF_GET_WHITE_SPEC_DATA
+        ak = L_deposit_h( BASOP_Util_Divide3216_Scale( W_shl_sat_l( window_sum, shift ), sub( stop, sub( i, level ) ), &tmp_e ) );
+        window_sum = W_sub( window_sum, W_mult_32_32( in[i - level], in[i - level] ) ); /* subtract the left one */
+        ak_e = add( tmp_e, eff_e );                                                     // tmp_e + 2 * (in_e - s_l) - 15
+#else
         Word64 temp = 0;
         move64();
 
@@ -2961,6 +2983,8 @@ static void IGF_getWhiteSpectralData_ivas(
 
         ak = L_deposit_h( BASOP_Util_Divide3216_Scale( W_shl_sat_l( temp, shift ), sub( stop, sub( i, level ) ), &tmp_e ) );
         ak_e = add( tmp_e, eff_e ); // tmp_e + 2 * (in_e - s_l) - 15
+#endif
+
         n = sub( ak_e, add( norm_l( ak ), 1 ) );
         n = shr( n, 1 );