Improve voice quality and naturalness

frontend/app/voice/page.tsx

@@ -64,13 +64,53 @@ export default function OraVoice() {
 
     const speak = (text: string) => {
         setState("SPEAKING");
+
+        // Cancel any ongoing speech
+        window.speechSynthesis.cancel();
+
         const utterance = new SpeechSynthesisUtterance(text);
-        // Try to find a nice voice
+
+        // Get available voices and select the best one
         const voices = window.speechSynthesis.getVoices();
-        const preferred = voices.find(v => v.name.includes("Google US English")) || voices[0];
-        if (preferred) utterance.voice = preferred;
+
+        // Priority order for natural-sounding voices
+        const preferredVoices = [
+            "Microsoft Zira - English (United States)",
+            "Google US English Female",
+            "Samantha",
+            "Karen",
+            "Moira",
+            "Tessa"
+        ];
+
+        let selectedVoice = voices.find(v =>
+            preferredVoices.some(pv => v.name.includes(pv))
+        );
+
+        // Fallback to any female English voice
+        if (!selectedVoice) {
+            selectedVoice = voices.find(v =>
+                v.lang.includes("en") && v.name.toLowerCase().includes("female")
+            );
+        }
+
+        // Final fallback
+        if (!selectedVoice && voices.length > 0) {
+            selectedVoice = voices[0];
+        }
+
+        if (selectedVoice) {
+            utterance.voice = selectedVoice;
+        }
+
+        // Voice parameters for warmth and naturalness
+        utterance.rate = 0.9;      // Slightly slower for clarity
+        utterance.pitch = 0.95;    // Slightly lower for warmth
+        utterance.volume = 1.0;    // Full volume
 
         utterance.onend = () => setState("IDLE");
+        utterance.onerror = () => setState("IDLE");
+
         window.speechSynthesis.speak(utterance);
     };