Unique new treatment reduces motion sickness without medication

Motion sickness affects people of all ages. Whether in cars, on boats, or in the air, the symptoms – nausea, dizziness, sweating – can turn travel into a miserable experience.

As transportation advances, especially with self-driving vehicles, more passengers may find themselves at the mercy of motion-induced discomfort. The need for a simple, safe solution has never been more urgent.

Scientists at Nagoya University Graduate School of Medicine may have found that solution – surprisingly, through the use of sound.

Their recent study, published in Environmental Health and Preventive Medicine, explores how a specific frequency of pure tone, delivered for just one minute, can reduce both the physical and emotional symptoms of motion sickness.

The research, led by Takumi Kagawa and Masashi Kato, combines insights from mouse models and human trials to build a compelling case for this unique acoustic intervention.

Motion sickness starts in the inner ear

Motion sickness is rooted in a conflict between visual input and signals from the inner ear’s balance organs.

When these systems send mismatched information to the brain, the result is confusion – and often, vomiting.

The inner ear’s otolithic organs, particularly the utricle, detect linear movements. Researchers focused on these structures, and aimed to influence their behavior using sound.

Their experiments identified a single, highly specific tone at 100 Hz that activates the utricle when delivered at safe sound pressure levels of 80–85 dBZ.

This tone, referred to in the study as “sound spice®,” had a measurable effect on ion channels in mouse utricles – especially when otoconia, small calcium carbonate crystals essential for balance, were present. Without otoconia, the sound had little effect. This indicated a precise biological interaction.

“Vibrations at the unique sound stimulate the otolithic organs in the inner ear, which detect linear acceleration and gravity,” Kato explained.

“This suggests that a unique sound stimulation can broadly activate the vestibular system, which is responsible for maintaining balance and spatial orientation.”

Testing sound therapy for motion sickness

To verify the tone’s effect, researchers first conducted beam balance tests on mice. These tests assess balance by scoring how well mice walk along a narrow beam.

Mice exposed to the 100 Hz tone for five minutes before being subjected to shaking performed better than those who received no sound.

Notably, the benefit lasted up to two hours. In contrast, mice exposed to a 250 Hz tone showed no such improvement.

Human trials followed. Participants, all with a history of motion sickness, were placed in swing chairs, immersive driving simulators, or vehicles.

To trigger discomfort, they were asked to read during the motion – an activity known to increase motion sickness. Before each session, they received either no sound or one minute of 100 Hz exposure via speakers near their ears.

Less dizziness, lower stress response

Balance was measured using posturography, a technique that tracks movement of the center of gravity.

Those who heard the tone showed smaller increases in envelope area, a marker of imbalance. Heart rate variability, which indicates how well the autonomic nervous system responds to stress, also improved.

Exposure to the tone boosted parasympathetic activity and reduced sympathetic dominance – the hallmark of stress and nausea.

“Our study demonstrated that short-term stimulation using a unique sound called ‘sound spice®’ alleviates symptoms of motion sickness, such as nausea and dizziness,” Kagawa said.

“The effective sound level falls within the range of everyday environmental noise exposure, suggesting that the sound technology is both effective and safe.”

Vehicle trials offer real-world proof

Of all the tests, the vehicle trials perhaps carried the most relevance to daily life. In these, participants sat in the rear seat of a car, reading during a series of stop-and-go movements.

Again, those exposed to the 100 Hz tone experienced less sway and reported fewer symptoms on the Motion Sickness Assessment Questionnaire (MSAQ).

This questionnaire covers several dimensions – gastrointestinal, central (like dizziness), peripheral (like cold sweating), and sopite-related symptoms (like drowsiness). All categories, except sopite-related, showed improvement after sound exposure.

“These results suggest that activation of sympathetic nerves, which are often dysregulated in motion sickness, was objectively improved by the unique sound exposure,” Kato explained.

Safe fix for motion sickness

Safety was a top concern. The sound levels used – 80 to 85 dBZ – are below workplace limits defined by the World Health Organization.

The one-minute duration further reduces any risk. Researchers also confirmed that the tone did not affect hearing, even when delivered directly toward the inner ears.

In fact, everyday environments sometimes contain similar sound levels, such as during conversation. What sets this tone apart is its purity, stability, and targeted frequency. Random environmental noise rarely meets all three of these criteria.

“The health risk of short-term exposure to our unique sound is minimal,” Kagawa said. “Given that the stimulus level is well below workplace noise safety standards, this stimulation is expected to be safe when used properly.”

Next generation of travel comfort

To be effective, the sound must meet four conditions: equal exposure to both ears, frequency of 100 Hz, sound pressure of 80–85 dBZ, and a duration of one minute.

Devices could be built into car headrests, airplane seats, or wearable audio gear. The simplicity of the system opens doors for wide use.

Researchers now plan to test the tone’s effects when used during motion rather than just before it. They also see potential in treating related conditions, like inner ear disorders.

A past study by the same group found benefits for people with Meniere’s disease when exposed to 100 Hz tones.

A future without motion sickness?

If the technology proves reliable during motion, it could make travel more bearable for millions. The system’s non-invasiveness and ease of use make it especially appealing.

It may even become a routine feature in self-driving cars, where passengers can’t always look outside to stabilize their sense of balance.

This small sound may soon create a big change – making sickness-free travel not just possible, but normal.

The study was published in the journal Environmental Health and Preventive Medicine.

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