100Hz Motion Relief
1:00
Session length

Instructions1 minute before the ride · both ears · set the volume with the side buttons — clearly audible, never uncomfortable.

WHY 100 Hz

Gu et al. 2025

Motion sickness follows vestibular dysfunction. A pure tone at 100 Hz is transduced by the otoconia — the calcium-carbonate crystals of the utricle and saccule — so it activates the otolith organs, not just the cochlea.

0 10 ms 20 ms A
Fig. 1 — s(t) = A · sin(2π f t), f = 100 Hz, period T = 1/f = 10 ms.
level LZ = 20 · log10( p / p₀ ) p₀ = 20 µPa
A-weighting LA = LZ − 19.1 dB ⇒ 80–85 dB(Z) = 60.9–65.9 dB(A)
dose texposure = 1 min before motion, bilaterally
100 Hz tone 80–85 dB(Z) Otoconia utricle · saccule Vestibular activation ↓ postural sway envelope area ↓ LF/HF sympathetic tone ↓ MSAQ subjective symptoms
Fig. 2 — sound energy → otoconia → vestibular activation → less imbalance and autonomic response.

Protocolbilateral, 1 minute, before motion. In mice a 5-minute exposure held for ≥ 120 min; unilateral exposure and 250 Hz did not work.

Gu Y, Ohgami N, He T, Kagawa T, Kurniasari F, Tong K, Li X, Tazaki A, Takeda K, Mouri M, Kato M. Just 1-min exposure to a pure tone at 100 Hz with daily exposable sound pressure levels may improve motion sickness. Environ Health Prev Med. 2025;30. doi:10.1265/ehpm.24-00247

Long exposure at high volume can damage hearing — keep both moderate. Stop immediately if you notice ringing, worsening dizziness or any discomfort. This app is not medical advice.