How do you implement text-to-speech or speech features in MAUI?

Use TextToSpeech.Default.SpeakAsync for TTS with options (locale, pitch, volume). For speech-to-text you'll need platform speech recognition behind an interface or a plugin, requesting microphone/speech permissions. TTS is cross-platform out of the box; recognition typically requires platform code.

await TextToSpeech.Default.SpeakAsync("Your order shipped",
    new SpeechOptions { Pitch = 1.0f, Volume = 0.8f });