Play audio during phone call

Question

I've created an app in Swift that uses Twilio & CallKit to make outgoing phone calls. During the phone call, I would like to play audio through the phone's ear speaker such as "You have been on this call for 2 minutes..." or at the least an one of the built in system audio sounds.

It would work similarly to how navigations apps work when they announce directions when you are on a call

How can I make this happen?

I've looked at some similar questions on here, but I couldn't get an answer or updated answer.

Answer 1

Found out one way to do this is by using the built in AVSpeechSynthesizer. Check out the code below

public func sayMessage(message: String) {
    do {
        try setCategory(AVAudioSessionCategoryPlayAndRecord)
        try setActive(true)
        let synth = AVSpeechSynthesizer()
        print("Routes:: \(currentRoute.outputs)")
        if let currentChannels = currentRoute.outputs.first?.channels {
            synth.outputChannels = currentChannels
            print("Found channels \(currentChannels)")
        }
        let myUtterance = AVSpeechUtterance(string: message)
        synth.speak(myUtterance)

    } catch {
        print(error)
    }
}