H 3 H 3 that is who boo.
The first occurrence of the multiple repeated knocks appears in Series 1 Episode 10 - The Loobenfeld Decay:Sheldon: (Knock, knock, knock, knock) Leonard, (Knock, knock, knock, knock) Leonard, (Knock, knock, knock, knock) Leonard...Sheldon: (Knock, knock, knock, knock) Penny, (Knock, knock, knock, knock) Penny, (Knock, knock, knock, knock)Penny, (door opens) Good morning.
Click on the door 3 times (knock knock knock).
that
Click on the door 3 times (knock knock knock).
Click on the door 3 times (knock knock knock).
Click on the door 3 times (knock knock knock).
Click on the door 3 times (knock knock knock).
The secret knock is knock knock, knock knock knock knock
Click on the door 3 times (knock knock knock).
Click on the door 3 times (knock knock knock).
Knock First - 2003 Alysha H- 2-21 was released on: USA: 2004
Hannah Montana - 2006 Knock Knock Knockin' on Jackson's Head 3-11 is rated/received certificates of: Australia:G