fix review comment

lib/synth-audio.js

@@ -354,7 +354,7 @@ const synthPolly = async(createHash, retrieveHash, logger,
 const synthGoogle = async(logger, {credentials, stats, language, voice, gender, text}) => {
   const client = new ttsGoogle.TextToSpeechClient(credentials);
   // If google custom voice cloning is used.
-  // At this time 31 Oct 2024, google node sdk has not support cloning voice yet.
+  // At this time 31 Oct 2024, google node sdk has not support voice cloning yet.
   if (typeof voice === 'object' && voice.voice_cloning_key) {
     try {
       const accessToken = await client.auth.getAccessToken();
@@ -383,8 +383,8 @@ const synthGoogle = async(logger, {credentials, stats, language, voice, gender,
         }
       };
 
-      const mp3 = await post('/v1beta1/text:synthesize', payload);
-      return Buffer.from(mp3.audioContent, 'base64');
+      const wav = await post('/v1beta1/text:synthesize', payload);
+      return Buffer.from(wav.audioContent, 'base64');
     } catch (err) {
       logger.info({err: await err.text()}, 'synthGoogle returned error');
       throw err;