当我在物理设备上使用AudioKit的AKMicrophoneTracker时,频率和振幅始终都是0。但在playground和iOS模拟器中,它运行完美。这是一个粗略的例子:classAppDelegate:UIResponder,UIApplicationDelegate{lettracker=AKMicrophoneTracker()funcapplication(_application:UIApplication,didFinishLaunchingWithOptionslaunchOptions:[UIApplicationLaunchOptionsKey:Any]?)->