     
     var currentRouteDescription: String {
         currentRoute.outputs.compactMap { device in
-            device.channels?.map {"\(device.shortPortName) \($0.shortChannelName)"}
-        }.flatMap{$0}.joined(separator: "\n")
+            device.portChannelDescription
+        }.compactMap{$0}.joined(separator: "\n")
     }
 }
 

        AVAudioSession.sharedInstance().outputIndexFor(channel: self)
    }
}

    var shortPortName: String {
        portName.stringByTrimmingWhiteSpace()
    }
    
    var portChannelDescription: String {
        guard let channels = channels else {
            return shortPortName
        }
        return channels.map {"\(shortPortName) - \($0.shortChannelName)"}.joined(separator: "\n")
    }
}

public extension AVAudioSessionChannelDescription {
