The sound of the shaman’s drum is very important. A shamanic ritual often begins with heating the drum head over a fire to bring it up to the desired pitch. It is the subtle variations in timbre and ever-changing overtones of the drum that allow the shaman to communicate with the spiritual realm. The shaman uses the drum to open portals to the spirit world and summon helping spirits. As Tuvan musicologist Valentina Suzukei explains, "There is a bridge on these sound waves so you can go from one world to another. In the sound world, a tunnel opens through which we can pass -- or the shaman’s spirits come to us. When you stop playing the drum, the bridge disappears."1
When a spirit is invoked, there is often an accompanying rhythm that evolves. Shamans frequently use specific rhythms to "call" their spirit helpers for the work at hand. A shaman may have a repertory of established rhythms or improvise a new rhythm, uniquely indicated for the situation. Shamans may strike certain parts of the drum to access particular helping spirits. The drumming is not restricted to a regular tempo, but may pause, speed up or slow down with irregular accents.
Shamans are also known for their ability to create unusual auditory phenomena. According to Scottish percussionist Ken Hyder, who has studied with Siberian shamans, "Shamans tend to move around a lot when they are playing, so a listener will hear a lot of changes in the sound…including a mini-Doppler effect. And if the shaman is singing at the same time, the voice will also change as its vibration plays on the drumhead."2 Furthermore, in a recent ethnographic study of Chukchi shamans, it was found that in a confined space, shamans are capable of directing the sound of their voice and drum to different parts of the room. The sounds appear to shift around the room, seemingly on their own. Shamans accomplish this through the use of standing waves, an acoustic phenomenon produced by the interference between sound waves as they reflect between walls. Sound waves either combine or cancel, causing certain resonant frequencies to either intensify or completely disappear. Sound becomes distorted and seems to expand and move about the room, as the shaman performs. Moreover, sound can appear to emanate from both outside and inside the body of the listener, a sensation which anthropologists claimed, "could be distinctly uncomfortable and unnerving."3
The Shaman's Horse
The drum -- sometimes called the shaman's horse -- provides the shaman a relatively easy means of controlled transcendence. Researchers have found that if a drum beat frequency of around 180 beats per minute is sustained for at least fifteen minutes, it will induce significant trance states in most people, even on their first attempt. During shamanic flight, the sound of the drum serves as a guidance system, indicating where the shaman is at any moment or where they might need to go. "The drumbeat also serves as an anchor, or lifeline, that the shaman follows to return to his or her body and/or exit the trance state when the trance work is complete."4
Recent studies have demonstrated that shamanic drumming produces deeper self-awareness by inducing synchronous brain activity. The physical transmission of rhythmic energy to the brain synchronizes the two cerebral hemispheres, integrating conscious and unconscious awareness. The ability to access unconscious information through symbols and imagery facilitates psychological integration and a reintegration of self. Drumming also synchronizes the frontal and lower areas of the brain, integrating nonverbal information from lower brain structures into the frontal cortex, producing "feelings of insight, understanding, integration, certainty, conviction, and truth, which surpass ordinary understandings and tend to persist long after the experience, often providing foundational insights for religious and cultural traditions."5
It takes abstract thinking and the interconnection between symbols, concepts, and emotions to make unconscious information meaningful. The human adaptation to translate an inner trance experience into meaningful narrative is uniquely exploited by singing, vocalizing, and drumming. Shamanic music targets perception, memory, and the complex emotions attached to symbols and concepts; the core functions humans rely on to formulate belief. Because of this exploit, the result of the synchronous brain activity in humans is the spontaneous generation of meaningful information which is imprinted into memory.