that hose is used to route blow by gases (oil vapors, etc) to your intake to be burned by the engine. effect is cleaner emissions as the oil vapors won't be polluting the atmosphere. pag malakas yung singaw, parang may bumubuga ng usok ng yosi, it's one of the signs of loose compression.

mahina pa naman eh, so ok lang yan, i'd advise you not to mess with it and leave it as is.