AVSpeechSynthesizer

One of the coolest features of AVSpeechSynthesizer is how it lets developers hook into speech events. An object conforming to AVSpeechSynthesizerDelegate can be called when a speech synthesizer starts or finishes, pauses or continues, and as each range of the utterance is spoken.

→ nshipster.com/avspeechsynthesizer/

The article highlights the role of Swift’s AVSpeechSynthesizer, introduced in iOS 7 and macOS 10.14, in enabling speech synthesis for computer-assisted communication across languages, supporting over 30 languages with voices selected via IETF Language Tags.

It allows developers to create AVSpeechUtterance objects to synthesise text, with customisable volume, pitch, and rate, and supports pausing at word boundaries for a smoother experience. Pronunciation can be fine-tuned using init(attributedString:) with AVSpeechSynthesisIPANotationAttribute for precise control, though documentation is limited, requiring settings adjustments or WWDC 2018 guidance.

The AVSpeechSynthesizerDelegate protocol enables real-time event handling, such as highlighting spoken words in a UI. By leveraging Swift’s clear syntax and safety, this API facilitates cross-lingual communication, reducing barriers in global interactions, as demonstrated in a Playground showcasing live text-highlighting for supported languages.