Update javascript.md

Author: sally-baolian

articles/ai-services/speech-service/includes/how-to/speech-synthesis/javascript.md

@@ -13,7 +13,7 @@ ms.custom: devx-track-js
 
 ## Select synthesis language and voice
 
-The text to speech feature in the Speech service supports more than 270 voices and more than 110 languages and variants. You can get the [full list](../../../language-support.md?tabs=tts) or try them in the [Voice Gallery](https://speech.microsoft.com/portal/voicegallery).
+The text to speech feature in the Speech service supports more than 400 voices and more than 140 languages and variants. You can get the [full list](../../../language-support.md?tabs=tts) or try them in the [Voice Gallery](https://speech.microsoft.com/portal/voicegallery).
 
 Specify the language or voice of `SpeechConfig` to match your input text and use the wanted voice: