What is the secret formula for scaring someone [No cheap scares!]

[Hardarm]

A nice idea could be that monster patrols around without the starting "roar" sound. (Easy to do it)
But without music, and the music will start if the player is nearby the forever patrolling monster (or it will go away if you do a certain thing)... Like in Penumbra Overture with the dogs. Apjjm should create a similar script