yes i know... event_playerstouch is called many times because the player is touching him a longer time.
try something like this:

my.skill1 = 0;

function event_playerstouch
{
event_type == event_impact && my.skill1 == 0)
{
my.skill1 = 1;
cyborg_h2_mdl_008 = ent_playsound(my, introduction,100);
wait(320);
my.skill1 = 0;
}
...

//not fine but works!!!