iPhone simulator 10.0 - Speech recognition unavailable - ios

Question

A newbie to swift! I am trying to implement an app that converts speech to text using speech recognizer.
Problem
SFSpeechRecognizer().isAvailable is false
private let request = SFSpeechAudioBufferRecognitionRequest()
private var task: SFSpeechRecognitionTask?
private let engine = AVAudioEngine()
func recognize() {
guard let node = engine.inputNode else {
return
}
let recordingFormat = node.outputFormat(forBus: 0)
node.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { buffer, _ in
self.recognitionRequest.append(buffer);
}
engine.prepare()
do {
try engine.start()
} catch {
return print(error)
}
guard let systemRecognizer = SFSpeechRecognizer() else {
return
}
if !systemRecognizer.isAvailable {
self.log(.debug, msg: "Entered this condition and stopped!")
return
}
}
Question
I am not sure why it stops in the simulator. Does microphone works in iPhone simulator?
Update
I tried testing with a audio file with below code,
let audioFile = Bundle.main.url(forResource: "create_activity", withExtension: "m4a", subdirectory: "Sample Recordings")
let recognitionRequest = SFSpeechURLRecognitionRequest(url: audioFile!)
getting error which says, Error Domain=kAFAssistantErrorDomain Code=1101 "(null)"

Answer 1

It looks that simulator has gained access to microphone with iOS 11.
Unfortunately I was not able to find any documentation confirming that, but can confirm this functionality with the following code sample. Works perfectly fine on iOS 11 simulator, but does nothing on iOS 10 simulator (or earlier).
import UIKit
import Speech
class ViewController: UIViewController {
private var recognizer = SFSpeechRecognizer()
private var request = SFSpeechAudioBufferRecognitionRequest()
private let engine = AVAudioEngine()
override func viewDidLoad() {
super.viewDidLoad()
requestPermissions()
}
private func requestPermissions() {
//
// Do not forget to add `NSMicrophoneUsageDescription` and `NSSpeechRecognitionUsageDescription` to `Info.plist`
//
// Request recording permission
AVAudioSession.sharedInstance().requestRecordPermission { allowed in
if allowed {
// Request speech recognition authorization
SFSpeechRecognizer.requestAuthorization { status in
switch status {
case .authorized: self.prepareSpeechRecognition()
case .notDetermined, .denied, .restricted: print("SFSpeechRecognizer authorization status: \(status).")
}
}
} else {
print("AVAudioSession record permission: \(allowed).")
}
}
}
private func prepareSpeechRecognition() {
// Check if recognizer is available (has failable initializer)
guard let recognizer = recognizer else {
print("SFSpeechRecognizer not supported.")
return
}
// Prepare recognition task
recognizer.recognitionTask(with: request) { (result, error) in
if let result = result {
print("SFSpeechRecognizer result: \(result.bestTranscription.formattedString)")
} else {
print("SFSpeechRecognizer error: \(String(describing: error))")
}
}
// Install tap to audio engine input node
let inputNode = engine.inputNode
let busNumber = 0
let recordingFormat = inputNode.outputFormat(forBus: busNumber)
inputNode.installTap(onBus: busNumber, bufferSize: 1024, format: recordingFormat) { buffer, time in
self.request.append(buffer);
}
// Prepare and start audio engine
engine.prepare()
do {
try engine.start()
} catch {
return print(error)
}
}
}
Do not forget to add NSMicrophoneUsageDescription and NSSpeechRecognitionUsageDescription to Info.plist.