Yes, it doesn't make sound. There is no sound as long as there is no observer. When a tree falls it make vibrations those vibrations are sound in the ears of the observer. Sound is a sensation. So when there is no receiver to this sensation then it's no longer a sensation. Vibrations take forms ( sound, image, smell, etc.) depending on the nature of actions and the organs receiving those vibrations.
Creation doesn't need to be observed to exist. Existence, Universe and Nature don't cease their movements; movements based on energy and vibrations. When we receive those vibrations under the forms we receive them, it doesn't mean that they are this way (in nature and universe ) just because we receive them that way through our senses.