"What is the sound of one hand clapping" is a well known Zen Buddhist Koan. Koans are questions whose answer cannot be arrived at through analytical mental processes - you can't think your way to the right answer.
The only route to the answer for a Koan is the instantaneous appreciation of the qustion at an intuitive or instinctive manner.
Resolving Koans trains the Zen student in this non-analytical mental process.
This means that simply telling you an answer to the Koan is a useless endeavor. There are books and papers written on the meaning of many Koans but none of these contain your answer.
This question has 2 answers. Either a one-hand clapping makes a lighter sound than a two-hand clapping when your one hand tries to slap its fingers to its palm. The other answer would be that it sounds like this:
The duration of One-Hand Clapping is 1.57 hours.
The Sound of One Hand Clapping was created in 1997.
One-Hand Clapping was created on 2001-08-17.
The Sound of One Hand Clapping has 425 pages.
The ISBN of The Sound of One Hand Clapping is 0-7329-0896-5.
The duration of The Sound of One Hand Clapping - film - is 1.55 hours.
The Sound of One Hand Clapping - film - was created on 1996-04-23.
The cast of One Hand Clapping - 2013 includes: Kyle Worthington as Alex
dubstep
The cast of One Hand Clapping - 1972 includes: Don Arioli Dave Broadfoot Judith Gault
no I'm not