Trees

"If a tree falls in a forest and no one is around to hear it, does it make a sound?"
This question was first posed in 1710.
In a similar vein, Albert Einstein is reported to have asked his fellow physicist and friend Niels Bohr, one of the founding fathers of quantum mechanics, whether he realistically believed that 'the moon does not exist if nobody is looking at it.'
It all depends on how you define sound. Since sound does not exist without our hearing of it, sound does not exist if we do not hear it. Yet the tree causes air waves to move and air travels so that if an electronic system was set up to record the event, it would record the activity.. But that isn't sound.
Sometimes things happen.. To others... when we're not there.... But that doesnt mean they didn't happen
Listen to the experience of others and learn.