How the reading works
The pasted text becomes one speech utterance. Its text, voice, rate, and pitch come from the controls, then the page calls speechSynthesis.speak(). The operating system's speech engine renders the words to audio: rate multiplies speaking speed (1.0 is normal), pitch raises or lowers the voice. Pause, Resume, and Stop map to the synthesizer's pause(), resume(), and cancel() calls; an end event fires when the utterance finishes.