Thank you again, my son has vocal tics which are noticeable but bearable but last Sunday he went swimming for the first time in ages and Monday he has started two different very loud noises so I am convinced the chlorine in the pool has started these. I am hoping that they will settle down again soon but will now look into buying L carnitine.
I am also thinking about eliminating dairy to see if this helps as I have read lots of stories on this.