Hi Michael,
Is it a long time speech? Take a look at:
Optimize media resources, flush is necessary if your
SpeechSynthesisStream is big enough.
Media files are some of the most common and expensive resources apps typically use. Because media file resources can greatly increase the size of your app's memory footprint, you must remember to release the handle to media as soon as the app is finished
using it.
--James
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Thanks
MSDN Community Support
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