iOS 27 beta 5 expands Siri's new voice customization features, adding Pace and Expressivity controls to all American voices and existing British voices, rather than limiting them to the two new US voices introduced earlier. Users can now adjust speaking speed and emotional emphasis across 12 supported voices using five levels for each setting. The feature relies on a new on-device voice model and requires recent hardware. Siri AI itself is expected to launch in beta later this year on devices starting with the iPhone 15 Pro.