The tube is inserted between the vocal cords, where the trachea begins. However in some people ( 1 - 2 % of the population ) the view is poor, making correct insertion difficult. The anaesthetist may have to try several times, with your head in different positions, and with different laryngoscopes or intubating guides called "introducers" ( or bougies ). Sometimes it may be safer to let you wake up, and do the intubation "awake" with a flexible fibereoptic intubating scope ( below ) .