What would cause chronic random and sudden deep inhalation of breath?

Brain activated: Two types of muscle: voluntary and involuntary. (eg., muscle of GI tract involuntary, Skeletal muscles are voluntary (but nervous system can override). But diaphragm (muscle for breathing) has both muscle types. So can breathe when U want, but U cannot stop!. Sudden deep breaths are called Sighs, brain does this to prevent lung collapse from low vol breathing at rest.