Okay, so the sound of one hand clapping may not be discernible to a lot of folk, but as the Zen masters postulate it to be a valid question, or koan, how would one answer?

Here’s Wikipedia’s definition of a koan: A kōan (公案; Japanese: kōan, Chinese: gōng-àn, Korean: gong’an, Vietnamese: công án) is a story, dialogue, question, or statement in the history and lore of Chán (Zen) Buddhism, generally containing aspects that are inaccessible to rational understanding, yet may be accessible to intuition. A famous kōan is: “Two hands clap and there is a sound; what is the sound of one hand?” (oral tradition, attributed to Hakuin Ekaku, 1686-1769, considered a reviver of the kōan tradition in Japan).

Get it?

In case not, here’s an explanation by a Zen master

What is the Sound of the Single Hand? When you clap together both hands a sharp sound is heard; when you raise the one hand there is neither sound nor smell. Is this the High Heaven of which Confucius speaks? Or is it the essentials of what Yamamba describes in these words: “The echo of the completely empty valley bears tidings heard from the soundless sound?” This is something that can by no means be heard with the ear. If conceptions and discriminations are not mixed within it and it is quite apart from seeing, hearing, perceiving, and knowing, and if, while walking, standing, sitting, and reclining, you proceed straightforwardly without interruption in the study of this koan, you will suddenly pluck out the karmic root of birth and death and break down the cave of ignorance. Thus you will attain to a peace in which the phoenix has left the golden net and the crane has been set free of the basket. At this time the basis of mind, consciousness, and emotion is suddenly shattered; the realm of illusion with its endless sinking in the cycle of birth and death is overturned.
From p. 164, Yabukoji, in The Zen Master Hakuin: Selected Writings, Translated by Philip B. Yampolsky, Columbia University Press, New York and London, 1971.

Jack Kerouac, in his Zen novel The Dharma Bums adds his take on koans with a humorous slant:

“‘Does a dog have Buddha nature or not?’ ‘Woof'”.
“If you have ice cream I will give you some.
If you have no ice cream I will take it away from you.”
(It is an ice cream kōan.)

So if you want to take this path towards enlightening that dormant urge for a higher consciousness, keep listening for that ‘sound’.