Is your feature request related to a problem? Please describe.
The speak icon doesn't have the ability to pause the speech, and if accidentally clicked on a long message, the user has to close the browser tab to fully terminate the speech.

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From the MDN docs, we could use .speaking and .pause() methods to

1. Show the pause icon when window.speechSynthesis.speaking is true
2. call the window.speechSynthesis.pause() function instead of .speak(message) in this function.

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