IOS Swift : UIAccessibilitySpeechAttributeIPANotation

Question

I am trying to make my app to speak in the IPANotation using AVSpeechSynthesizer, but it not working below is my code snippet,

let synthesizer = AVSpeechSynthesizer()

let attributedStr = NSMutableAttributedString(string: "Hello iPhone")
attributedStr.addAttribute(NSAttributedString.Key(UIAccessibilitySpeechAttributeIPANotation), value: "ˈa͡ɪ.ˈfo͡ʊn", range: NSRange(location: 6, length: 6))

let utterance = AVSpeechUtterance(attributedString: attributedString)
synthesizer.speak(utterence)

Thanks

Answer 1

Try the code snippet hereafter (iOS 12 - Swift 5.0) :

let attrStr = NSMutableAttributedString(string: "hello my little ")

let pronunciationKey = NSAttributedString.Key(rawValue: AVSpeechSynthesisIPANotationAttribute)
let attrStr2 = NSMutableAttributedString(string: "blablabla",
                                         attributes: [pronunciationKey: "ˈa͡ɪ.ˈfo͡ʊn"])

let finalAttrStr = NSMutableAttributedString()
finalAttrStr.append(attrStr)
finalAttrStr.append(attrStr2)

let utterance = AVSpeechUtterance(attributedString: finalAttrStr)
utterance.voice = AVSpeechSynthesisVoice(language: "en-GB")

let synthesizer = AVSpeechSynthesizer()
synthesizer.speak(utterance)

This is not perfect but it makes the IPA notation work using AVSpeechSynthesizer.

Another example is also available to figure out how to get the phonemes and put them into the code.