What is Buddhist doctrine on the question of counterfactual definiteness?

Counterfactual definiteness is, "is the ability to speak "meaningfully" of the definiteness of the results of measurements that have not been performed." The classic question to illustrate is, "When a tree falls in a lonely forest, and no animal is near by to hear it, does it make a sound? Why?" Another classic example is Einstein asking Bohr whether he really believed that, "the moon does not exist if nobody is looking at it?" What does Buddhism have to say about these questions if anything at all? The standard procedure for understanding anatta is to investigate and look for the self and upon not finding it concluding that the self does not exist as we imagined. However, doesn't this procedure implicitly rely upon the supposition that existing things can be found if one investigates and looks for them? That which can't be observed must not truly exist? Couldn't someone relying upon counterfactual definiteness just say that even though we can't observe the self that it still truly exists just like an unobserved tree in the forest that falls still makes a real sound?