There are different ways to take over the World. But there is only one way to take over the Universe and that’s through meditation.
~Aishwarya Shiva Pareek
Religion Facts says, "Singing bowls are used throughout the Himalayas in monasteries and homes to aid meditation. The sound of a singing bowl can be used to mark the beginning or end of a meditation period, or during meditation to focus the mind."
You can read more about them here or just take a listen (I think maybe this video is so long so people can sleep with it on):
Tibetan singing bowls give up their chaotic secrets
by Jason Palmer (BBC News)