Inserting, locking, unlocking and removing the keys of door lock.
Several variations of each separate sound :
key_inserting_1 : 1 sec
door_1_lock : 1 sec
door_1_unlock : 1 sec
door_2_lock : 1 sec
door_2_unlock : 2 sec
key_removing_1 : 1 sec
key_inserting_2 : 1 sec
door_3_lock : 1 sec
door_3_unlock : 1 sec
door_4_lock : 1 sec
door_4_unlock : 1 sec
key_removing_2 : 1 sec