diff --git a/sw_usb_audio/app_usb_aud_fosi_c1/CMakeLists.txt b/sw_usb_audio/app_usb_aud_fosi_c1/CMakeLists.txt
index e60b057..fa20ef3 100644
--- a/sw_usb_audio/app_usb_aud_fosi_c1/CMakeLists.txt
+++ b/sw_usb_audio/app_usb_aud_fosi_c1/CMakeLists.txt
@@ -144,8 +144,8 @@ set(APP_COMPILER_FLAGS_fps_uac1  ${SW_USB_AUDIO_FLAGS}            -DXUA_SPDIF_RX
                                                                   -DCHAN_BUFF_CTRL=1
                                                                   -DXUD_PRIORITY_HIGH=1
                                                                   -DHID_CONTROLS=1
-                                                                  -DDNR_50MS=1
-                                                                  -ldnr_50ms
+                                                                  #-DDNR_50MS=1
+                                                                  #-ldnr_50ms
                                                                   #-DDEBUG_MEMORY_LOG_ENABLED=1
                                                                   -DNO_LOG_TIMESTAPS=0
                                                                   -DI2S_CHANS_ADC=2)
diff --git a/sw_usb_audio/app_usb_aud_fosi_c1/src/extensions/dnr/dnr_dsp.c b/sw_usb_audio/app_usb_aud_fosi_c1/src/extensions/dnr/dnr_dsp.c
index 1f2a3c2..7a88951 100644
--- a/sw_usb_audio/app_usb_aud_fosi_c1/src/extensions/dnr/dnr_dsp.c
+++ b/sw_usb_audio/app_usb_aud_fosi_c1/src/extensions/dnr/dnr_dsp.c
@@ -40,6 +40,7 @@ void Aizip_DNR_init(void);
 
 void dnr_dsp_proc_task(void)
 {
+#if DNR_50MS || DNR_11MS
     Aizip_DNR_init();
     while(1) {
         unsigned dsp_eof = 0;
@@ -49,4 +50,5 @@ void dnr_dsp_proc_task(void)
             start_dsp_processing();
         }
     }
+#endif
 }
diff --git a/sw_usb_audio/app_usb_aud_fosi_c1/src/extensions/dnr/dnr_dsp_buf.c b/sw_usb_audio/app_usb_aud_fosi_c1/src/extensions/dnr/dnr_dsp_buf.c
index ab685e8..3a4336b 100644
--- a/sw_usb_audio/app_usb_aud_fosi_c1/src/extensions/dnr/dnr_dsp_buf.c
+++ b/sw_usb_audio/app_usb_aud_fosi_c1/src/extensions/dnr/dnr_dsp_buf.c
@@ -81,7 +81,8 @@ azp_dnr_param_t pram = {
 unsigned dnr_init_flag = 0;
 void Aizip_DNR_init(void)
 {
-    delay_microseconds(10000);
+#if DNR_50MS || DNR_11MS
+    delay_microseconks(10000);
    // setFlashPortPins(XS1_PORT_1B,XS1_PORT_1C,XS1_PORT_4B, XS1_CLKBLK_3);
 
     swlock_acquire(&flash_lock);
@@ -89,13 +90,16 @@ void Aizip_DNR_init(void)
     swlock_release(&flash_lock);
     dnr_init_flag = 1;
     debug_printf("AI_DNR_init status %d\n", sta);
+#endif
 }
 
 void start_dsp_processing(void)
 {
+#if DNR_50MS || DNR_11MS
     float level = -200;
 
     setNoisy_mix_factor(level);
 
     AI_DNR_Processing((int32_t *)&dsp_dnr_frame_buf[processing_buf_slot][0][0]);
+#endif
 }