iOS check if application has access to microphone

You can check the with recordPermission(), which has been available since iOS 8.

Keep in mind that starting with iOS 10, you must set the NSMicrophoneUsageDescription property in your info.plist for microphone permissions and include a message for the user. This message is shown to the user at time of the request. Finally, if localizing your app, be sure to include your plist strings for translation.

Failure to do so will result in a crash when attempting to access the microphone.

This answer has been cleaned up again for Swift 5.x

import AVFoundation

    switch AVAudioSession.sharedInstance().recordPermission {
    case .granted:
        print("Permission granted")
    case .denied:
        print("Permission denied")
    case .undetermined:
        print("Request permission here")
        AVAudioSession.sharedInstance().requestRecordPermission({ granted in
            // Handle granted
        })
    @unknown default:
        print("Unknown case")
    }

Objective-C

I have tested this code with iOS 8 for the purpose of checking for microphone permission and obtaining the current state.

switch ([[AVAudioSession sharedInstance] recordPermission]) {
    case AVAudioSessionRecordPermissionGranted:

        break;
    case AVAudioSessionRecordPermissionDenied:

        break;
    case AVAudioSessionRecordPermissionUndetermined:
        // This is the initial state before a user has made any choice
        // You can use this spot to request permission here if you want
        break;
    default:
        break;
}

As always, make sure to import AVFoundation.