Sound meditation uses acoustic vibration — singing bowls, gongs, tuning forks, or chanting — as the object of mindful attention. A sound bath is an immersive experience in which participants lie down while a practitioner plays instruments around them, creating a wash of resonant sound that facilitates deep relaxation and meditative states. Tibetan singing bowls, used in Buddhist rituals for centuries, are the most common instruments. Research suggests that sound meditation reduces anxiety, tension, and negative mood significantly compared to baseline, and may produce states of focused attention comparable to traditional breath meditation for people who find breath-based practice difficult.

Reference:

Wikipedia: Tibetan Singing Bowl

https://en.wikipedia.org/wiki/Tibetan_singing_bowl