okay so it's not an interference. next thing to work out is which speakers are playing. you have a load speaker for music , alarms and loadspeaker calls and 1 regular speaker for misc. can you load a game that you know bugs and try putting both speakers by your ear and try to work out if both or 1 is causing this ( usually both speakers will play music ) it may be one or the other or both. it's also worth checking of theres a pattern such as online games or if the files of said games are stored locally. does this happen if you are watching youtube? if not what about downloading a video or song? i suspect a core sound file is corruped or a physical part is damaged or faulty.
