Instrument Resonances

Tuning Fork — C128 (Otto Fork)

128.00 Hz

Note: C3

Cosmic Octave Color

Derived visible color (533 nm)

Display swatch #73c236

EstablishedInstrument / Acoustic Reference

Evidence Level

Established

Source Count

Last Reviewed

March 23, 2026

Directly measured, standardized, or well-supported in mainstream scientific or technical literature.

This entry describes an instrument or resonance reference. Therapeutic outcomes depend on context, level, instrument build, and listener response.

Review the evidence model

The 128 Hz "Otto" tuning fork (C3) is widely used in sound healing, placed directly on the body. Also used medically in bone conduction hearing tests. C128 = 2^7 Hz.

Wavelength

2.68 m

Nearest Note

C3 (-38¢)

Claim Type

Instrument / Acoustic Reference

Cosmic Octave Color

Derived visible color (533 nm) · #73c236

Source

Sound healing / osteopathy

Sources

Traditional and Practitioner Sound Sources

1 atlas references

Historical, cultural, and practitioner sources used to document how frequencies are talked about in practice communities.

Traditional and practitioner sound-healing sources.

Historical Use

Used in sound healing placed on the body (Otto tuner). Also used in medical bone conduction tests.

instrumenttuning-forkottohealing