Detect hardware sample rate iOS

    func getSampleRate() {
        var session: AVAudioSession = AVAudioSession.sharedInstance()
        var audioSessionError: NSError?
        session.setCategory(AVAudioSessionCategoryPlayback, error:&audioSessionError)
        if (audioSessionError != nil) {
            println("Error \(audioSessionError?.code), (audioSessionError?.localizedDescription)")
        }

        var bufferDuration = NSTimeInterval(0.005)
        session.setPreferredIOBufferDuration(bufferDuration, error:&audioSessionError)
        if (audioSessionError != nil) {
            println("Error \(audioSessionError?.code), (audioSessionError?.localizedDescription)")
        }

        var sampleRate = 88200.0
        session.setPreferredSampleRate(sampleRate, error:&audioSessionError)
        if (audioSessionError != nil) {
            println("Error \(audioSessionError?.code), (audioSessionError?.localizedDescription)")
        }

        NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("handleRouteChange:"), name:AVAudioSessionRouteChangeNotification, object: session)

        session.setActive(true, error:&audioSessionError)
        if (audioSessionError != nil) {
            println("Error \(audioSessionError?.code), (audioSessionError?.localizedDescription)")
        }

        sampleRate = session.sampleRate
        bufferDuration = session.IOBufferDuration
        println("Sample Rate: \(sampleRate)HZ I/O Buffer Duration:\(bufferDuration)")

    }

    func handleRouteChange(object:AnyObject) {
        println("Got route change for playback")
        getSampleRate()
    }