Text to speech - AVSpeechSynthesizer

I have a question on AVSpeechSynthesizer API which performs “Text to speech” on iOS device.

I know “Text to speech” works fine in offline.

When the mobile is connected to the internet, whether the “Text to Speech” API(TTS Engine) contacts Apple sever for better performance.

Text to speech - AVSpeechSynthesizer
 
 
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