diff --git a/apps/sim/app/api/proxy/tts/stream/route.ts b/apps/sim/app/api/proxy/tts/stream/route.ts
index d8ea97d39cf..39d561522a9 100644
--- a/apps/sim/app/api/proxy/tts/stream/route.ts
+++ b/apps/sim/app/api/proxy/tts/stream/route.ts
@@ -92,7 +92,8 @@ export const POST = withRouteHandler(async (request: NextRequest) => {
       return new Response('ElevenLabs service not configured', { status: 503 })
     }
 
-    const endpoint = `https://api.elevenlabs.io/v1/text-to-speech/${voiceId}/stream`
+    const query = new URLSearchParams({ output_format: 'mp3_44100_128' })
+    const endpoint = `https://api.elevenlabs.io/v1/text-to-speech/${voiceId}/stream?${query.toString()}`
 
     const response = await fetch(endpoint, {
       method: 'POST',
@@ -104,17 +105,13 @@ export const POST = withRouteHandler(async (request: NextRequest) => {
       body: JSON.stringify({
         text,
         model_id: modelId,
-        optimize_streaming_latency: 4,
-        output_format: 'mp3_22050_32', // Fastest format
         voice_settings: {
           stability: 0.5,
           similarity_boost: 0.8,
           style: 0.0,
           use_speaker_boost: false,
         },
-        enable_ssml_parsing: false,
-        apply_text_normalization: 'off',
-        use_pvc_as_ivc: false,
+        apply_text_normalization: 'auto',
       }),
     })
 
diff --git a/apps/sim/app/chat/[identifier]/chat.tsx b/apps/sim/app/chat/[identifier]/chat.tsx
index f5678291c87..891727d5784 100644
--- a/apps/sim/app/chat/[identifier]/chat.tsx
+++ b/apps/sim/app/chat/[identifier]/chat.tsx
@@ -44,7 +44,7 @@ interface ChatRequestPayload {
 }
 
 const DEFAULT_VOICE_SETTINGS = {
-  voiceId: 'EXAVITQu4vr4xnSDxMaL', // Default ElevenLabs voice (Bella)
+  voiceId: 'cgSgspJ2msm6clMCkdW9', // Default ElevenLabs voice (Jessica) — Flash v2.5-optimized
 }
 
 /**
diff --git a/apps/sim/app/chat/hooks/use-audio-streaming.ts b/apps/sim/app/chat/hooks/use-audio-streaming.ts
index 6ba5b5d9aab..51db6974402 100644
--- a/apps/sim/app/chat/hooks/use-audio-streaming.ts
+++ b/apps/sim/app/chat/hooks/use-audio-streaming.ts
@@ -79,7 +79,7 @@ export function useAudioStreaming(sharedAudioContextRef?: RefObject<AudioContext
     const { text, options } = item
     const {
       voiceId,
-      modelId = 'eleven_turbo_v2_5',
+      modelId = 'eleven_flash_v2_5',
       chatId,
       onAudioStart,
       onAudioEnd,
diff --git a/apps/sim/lib/api/contracts/media/tts-stream.ts b/apps/sim/lib/api/contracts/media/tts-stream.ts
index 4b7433c82ed..d692d933f91 100644
--- a/apps/sim/lib/api/contracts/media/tts-stream.ts
+++ b/apps/sim/lib/api/contracts/media/tts-stream.ts
@@ -5,7 +5,7 @@ export const ttsStreamBodySchema = z
   .object({
     text: z.string().min(1),
     voiceId: z.string().min(1),
-    modelId: z.string().optional().default('eleven_turbo_v2_5'),
+    modelId: z.string().optional().default('eleven_flash_v2_5'),
     chatId: z.string().min(1),
   })
   .passthrough()