diff --git a/audio/audio_hw.cpp b/audio/audio_hw.cpp
index 7678423..7ecfa1f 100755
--- a/audio/audio_hw.cpp
+++ b/audio/audio_hw.cpp
@@ -83,6 +83,11 @@ struct pcm_config pcm_config_in = {
 };
 #endif
 
+/* store previous audio format for nugu_playback */
+static AMP_SND_SPDIF_FORMAT gSpdifFormat = AMP_SND_SPDIF_FORMAT_INVALID;
+static AMP_SND_HDMI_FORMAT gHdmiFormat = AMP_SND_HDMI_FORMAT_INVALID;
+
+
 static uint32_t out_get_sample_rate(const struct audio_stream *stream)
 {
     ENTER("stream=%p", stream);
@@ -1219,6 +1224,26 @@ static int adev_set_parameters(struct audio_hw_device *dev,
 			gDevConStatus.nugu_playback_enabled = true;
 			bAudioRouteChange = true;
 
+                        // save audio format
+                        AMP_SND_GetSpdifFormat(&gSpdifFormat);
+                        AMP_SND_GetHDMIFormat(&gHdmiFormat);
+
+                        // set output mode as PCM or PCM multi when nugu is on
+                        if(gHdmiFormat != AMP_SND_HDMI_FORMAT_PCM_MULTI) {
+                            ret = AMP_SND_SetSpdifFormat(AMP_SND_SPDIF_FORMAT_STEREO_PCM);
+                            if( ret != SUCCESS ) {
+                                MVLOGE("fail to set AMP_SND_SetSpdifFormat() to AMP_SND_SPDIF_FORMAT_STEREO_PCM!!!");
+                            } else {
+                                MVLOGD("change to Spdif format to PCM.");
+                            }
+                            ret = AMP_SND_SetHDMIFormat(AMP_SND_HDMI_FORMAT_PCM_MULTI);
+                            if( ret != SUCCESS ) {
+                                MVLOGE("fail to set AMP_SND_SetHDMIFormat () to AMP_SND_HDMI_FORMAT_PCM_MULTI!!!");
+                            } else {
+                                MVLOGD("change to HDMI format to PCM.");
+                            }
+                        }
+
 			//Enable AMP when NUGU is playing.
 			isAmpOn = property_get_int32(PROPERTY_VENDOR_AMP_STATUS, 1);
 			if(isAmpOn == 0){ //AMP is off
@@ -1237,6 +1262,22 @@ static int adev_set_parameters(struct audio_hw_device *dev,
 			//Fii add end; River 2022/07/17
 			gDevConStatus.nugu_playback_enabled = false;
 			bAudioRouteChange = true;
+
+                        // Change output format as saved one.
+                        if(gHdmiFormat != AMP_SND_HDMI_FORMAT_INVALID) {
+                        ret = AMP_SND_SetSpdifFormat(gSpdifFormat);
+                        if( ret != SUCCESS ) {
+                            MVLOGE("fail to set AMP_SND_SetSpdifFormat() to (%d)!!!", gSpdifFormat);
+                        } else {
+                            MVLOGD("change to Spdif format to (%d).", gSpdifFormat);
+                        }
+                        ret = AMP_SND_SetHDMIFormat(gHdmiFormat);
+                        if( ret != SUCCESS ) {
+                            MVLOGE("fail to set AMP_SND_SetHDMIFormat () to (%d)!!!", gHdmiFormat);
+                        } else {
+                            MVLOGD("change to HDMI format to (%d).", gHdmiFormat);
+                        }
+                    }
 		}
 	}