diff --git a/service/llm_service.go b/service/llm_service.go
index 91c4ee3..e980d4c 100644
--- a/service/llm_service.go
+++ b/service/llm_service.go
@@ -718,7 +718,7 @@ func (s *LLMService) DeleteConversation(conversationID, user string) (map[string
 // SynthesizeSpeech converts text to speech
 func (s *LLMService) SynthesizeSpeech(text string, audio string) (*SpeechResponse, error) {
 	payload := SpeechRequest{
-		Model:         "speech-02-turbo",
+		Model:         "speech-02-hd",
 		Text:          text,
 		Stream:        false,
 		LanguageBoost: "auto",
@@ -727,8 +727,8 @@ func (s *LLMService) SynthesizeSpeech(text string, audio string) (*SpeechRespons
 			VoiceID: audio,
 			Speed:   1,
 			Vol:     1,
-			Pitch:   0,
-			Emotion: "happy",
+			Pitch:   -1,
+			Emotion: "neutral",
 		},
 		AudioSetting: AudioSetting{
 			SampleRate: 32000,