Scientists discover intriguing brainwave patterns linked to rhythmic sound meditation

A recent study published in the Annals of Neurosciences suggests that practicing a specific type of sound-based meditation can quiet electrical brain activity while simultaneously increasing a person’s sense of alertness. These findings provide evidence that listening to and focusing on rhythmic sounds may induce a unique mental state. This state is characterized by deep physical relaxation paired with sharp mental clarity.

Rhythmic sound meditation is a structured practice that involves focusing one’s attention on a specific repetitive auditory cue. In this particular study, participants focused on the spoken syllable “AUM.” The guided practice directs a person to gradually shift their attention from listening to the external sound to experiencing a state of internal silence. Historically, this technique is known as Nadamay Meditation and is rooted in ancient Indian philosophical texts.

The researchers designed the study to understand how this specific type of auditory meditation affects brain function. Most previous studies on mindfulness practices tend to show an increase in certain brainwaves associated with relaxation and focus. However, some practices aimed at achieving a state of mental emptiness tend to show the opposite effect. These techniques often result in a general decrease in electrical activity across the brain.

The scientists wanted to map the exact brain patterns produced by rhythmic sound meditation to see which category it fell into. They wanted to determine if focusing on a rhythmic sound would quiet the brain’s electrical signals or amplify them. They also hoped to track whether any changes in brain activity would directly affect how awake and aware the participants felt after the session.

“The primary motivation was to address a notable gap in the neuroscientific literature. While meditation research has grown substantially over the past two decades, the vast majority of studies have focused on silent, mindfulness-based practices such as focused attention or open monitoring meditation. Structured sound-based meditation traditions, despite having deep historical roots, have remained largely unexplored from a neurophysiological standpoint,” said study author Km Megha, a PhD scholar at the Central University of Rajasthan.

“The practice we examined, rhythmic sound meditation, is rooted in the ancient Indian tradition of Nada Yoga, described in classical texts such as the Nada Bindu Upanishad, which outlines sound as a pathway to altered states of consciousness. We wanted to examine whether these experiential claims had measurable neurophysiological correlates using contemporary EEG methodology.”

The researchers recruited fifteen healthy adults with an average age of about twenty-five. None of the participants had any previous experience with meditation or similar mindfulness practices. Each person took part in two separate twenty-six-minute sessions on different days. One session involved the sound meditation, and the other involved a resting state.

During the meditation session, participants practiced the guided rhythmic sound technique while keeping their eyes closed. In the resting session, they simply rested in a chair with their eyes closed and let their thoughts wander naturally. The scientists randomized the order of these visits so that some participants meditated first, while others completed the resting phase first.

Before and after each session, participants rated their current level of wakefulness using a standard questionnaire called the Stanford Sleepiness Scale. This survey asks individuals to rank how alert or tired they feel at that exact moment. During the full twenty-six minutes of both sessions, the researchers continuously monitored the participants’ brain activity. They used an electroencephalogram, which is a device that records electrical brainwaves through sixty-four sensors placed harmlessly on the scalp.

The device measures different types of brainwaves, which vibrate at various speeds and indicate different mental states. These include slow rhythms like delta and theta waves, which usually appear during sleep, deep relaxation, or daydreaming. The electroencephalogram also tracks faster rhythms like alpha, beta, and gamma waves. These faster waves are typically associated with active thinking, problem-solving, sensory processing, and deep concentration.

The scientists found that rhythmic sound meditation reduced the electrical power of all five types of brainwaves compared to the resting session. This reduction was most prominent in the frontal and central parts of the brain. The frontal lobe is a brain region heavily involved in attention, planning, and self-awareness. A decrease in activity here suggests that the participants were experiencing less mind-wandering and fewer distracting thoughts.

At the same time, the self-reported survey revealed an opposing pattern regarding the participants’ wakefulness. Before the resting session, about ninety-three percent of the participants felt alert. That number dropped to about seventy-three percent after resting, indicating that sitting quietly made them feel drowsy.

In contrast, about eighty-seven percent of the participants felt alert before the meditation session began. This number actually increased to over ninety-three percent after they finished meditating. The researchers noted that this combination of quiet brain activity and heightened wakefulness is highly unusual. Usually, a widespread drop in brainwave power means a person is falling asleep or losing focus.

“Perhaps the most striking finding was what we call the ‘alertness paradox,’” Megha told PsyPost. “Conventionally, widespread EEG power suppression is associated with drowsiness or cognitive disengagement. We anticipated some degree of power reduction, but the simultaneous increase in subjective alertness with 93.3% of meditation participants reporting heightened alertness post-session compared to only 73.3% after the resting state, was notably unexpected. This dissociation between oscillatory suppression and conscious alertness suggests that rhythmic sound meditation may induce an active, attentive state of mental quietude, rather than passive relaxation.”

“The central takeaway is that not all forms of meditation work the same way in the brain. Our findings suggest that rhythmic sound meditation produces a distinctive state, one characterized by reduced oscillatory brain activity, particularly in the frontal regions, yet accompanied by heightened subjective alertness. In plain terms, participants’ brains became measurably quieter, yet they felt more awake and mentally clear afterward. This combination is quite different from simply resting or relaxing, and it points toward a unique neurological state that deserves further scientific attention.”

As with all research, there are limitations to consider. The study relied on a very small sample size of just fifteen people. This means the results might not apply universally to the general population. The scientists note that larger studies with more diverse groups of people are necessary to confirm these initial patterns.

Another limitation is that the study used a self-reported questionnaire to measure alertness rather than objective cognitive tests. Relying entirely on how a participant feels can sometimes lead to biased results. Participants might expect to feel better or more awake simply because they know they are meditating. Future research should include physical behavioral tasks, such as computerized reaction time tests, to verify whether the participants are actually more alert.

The study also lacked an active control condition, such as having participants listen to a podcast or classical music. This makes it difficult to completely isolate the specific effects of the meditation from general relaxation. Finally, the surface-level brain sensors used in this study cannot pinpoint exactly which deep brain networks are involved in the process. Advanced imaging techniques are needed to look deeper into the brain and map the specific neural pathways affected by rhythmic sounds.

“We are planning to extend this line of research in several directions: replicating the study with larger and more demographically diverse samples, comparing the neurophysiological effects in long-term practitioners versus beginners, and exploring the potential clinical applications of rhythmic sound meditation for conditions such as chronic stress, anxiety, and sleep disturbance,” Megha explained. “We are also interested in examining how the specific acoustic properties of rhythm, frequency, and tonal structure, map onto distinct EEG signatures.”

Ultimately, the research team hopes these preliminary results help clarify how physical relaxation and mental focus can coexist. They caution against the assumption that a drop in electrical brain energy equals a decline in awareness.

“We would like to emphasize that reduced EEG power does not mean reduced cognitive function,” Megha told PsyPost. “There is a tendency in popular science communication to equate ‘brain activity’ with cognitive performance or mental effort. In this context, the frontal power suppression we observed is more consistent with what some researchers describe as ‘neural efficiency’ or a state of reduced self-referential processing, an organised quieting of the mind, not a disengagement from it.”

“We hope this study contributes to a broader scientific acknowledgment that sound-based contemplative traditions represent a rich and underexplored domain for neuroscientific inquiry. The practice examined here has been part of living contemplative traditions for centuries, and bringing it into the laboratory is as much an act of cross-cultural scientific dialogue as it is an empirical investigation.”

“We also wish to note that this practice is more fully known as ‘Nadamay Meditation,’ a name that better reflects its philosophical and sonic foundations,” Megha added. “We used the term rhythmic sound meditation in the study for clarity and accessibility within the scientific literature.”

The study, “Sound-based Meditation Alters Brain Activity: EEG Evidence for Power Reduction and Enhanced Conscious Alertness,” was authored by Km Megha, Ankita Mishra, Raksha Sharma, Pallabi Pal, Vijay Shanker Yadav, Arjun Ram Roja, Arun Sasidharan, Gulshan Kumar, and Sanjib Patra.