Motorcycle Repair: engine noise, netural, emergency lights

Question
i have 2004 1200 custom not smoking no emergency lights on but am hearing loud noise in motor or in tranny  but still runs and shifts normally.

Answer
Couple of questions. Does the noise happen at idle? Under acceration? When you are riding steady?  If the bike is sitting there in netural and idling do you hear it? You also need to try to locate the noise. Top end, bottom end, trans? You can get a straw or a small tube and put it to your ear and listen all over the motor to see if you can locate where the sound is coming from.
Waiting for your responce
Mike