Though research has been done on the benefits of Tibetan singing bowls, We must consider the centuries of which the ancient Tibetans have successfully used such a tool. Physiological and Psychological  effects have been documented in studies where the singing bowl was in use.
I offer this for free as part of my treatments not only because the tone in which the brass bowl resonates, it has been known to enhances the dissolution of anger, anxiety, pressure, depression, or pain. As well as regulating blood pressure, respiratory and heart rate. This sound soothes the nervous system and helps pull you out of your head and focus you softly back into the body. This tender type of meditation wildly personifies that reconnection we deeply need in order to release, unwind and destress. 

The frequencies of which specific Hrtz are measured to have a way of penetrating one's biofield. Have you heard of the biofield? That invisible yet not exactly intangible energy field that surrounds and pervades all living things? 

The resonating Hrtz of Tuning forks help restore homeostasis within a disturbed biofield. When you activate a tuning fork and use it near or on the body, the vibrations it gives off is like a cheer leader for the various layers in our body to restore homeostasis sympathetically. Layers like the cells, tissues, and chakras! This can include physical and emotional disruptions that have not been resolved or healed.