Tuning Fork Activator, Rubber

Quick Answer: The Tuning Fork Activator, Rubber is a rubber striker used to set a tuning fork vibrating: tapping a prong on the soft rubber excites the fork’s fundamental note cleanly, without the metallic clang, extra overtones and prong damage caused by striking it on a bench or other hard object.

Why Forks Are Struck on Rubber

A tuning fork is designed to vibrate at one frequency, usually stamped on its stem. When it is struck against something hard, however, the impact also excites higher-frequency modes, heard as a brief metallic ring, and repeated knocks on bench edges nick and bend the prongs, which slowly shifts the frequency. A rubber tuning fork activator gives a softer, broader impact that mainly excites the fundamental and does no harm to the metal.

Rubber activators are made as small rubber-headed mallets or as rubber pads or blocks that the fork is struck against. This listing is described only as a rubber activator, so its form should be checked with the order. Either way, the fork is held by its stem and one prong is tapped firmly but not violently.

In physics labs the activator is used in the resonance tube experiment for the speed of sound, in sonometer experiments on the frequency of a stretched wire, and in demonstrations of beats. A Wireless Sound Sensor can display the fork’s waveform and show how much cleaner the rubber-struck note is. Medical and audiology students also use tuning forks for the Rinne and Weber hearing tests, which call for a gently struck fork.

Specifications

Applications

• Resonance tube (resonance column) experiments to find the speed of sound in air.
• Sonometer experiments relating a wire’s vibrating length to the fork frequency.
• Beats demonstrations with two forks of slightly different frequency.
• Rinne and Weber hearing tests in medical and audiology training.

Care & Handling

• Strike with the rubber face only, and never use the bench as a substitute when the activator is missing.
• Keep the rubber clean and free of grit, which would scratch the fork.
• Store it away from sunlight and heat to stop the rubber hardening.

Why Choose LabEquip

Physics departments setting up sound experiments and colleges training audiology or medical students buy rubber activators with their fork sets, usually one per bench. LabEquip lists it under General Lab Products, while the sound apparatus it serves appears among the physics lab products; orders can be placed through the contact page.

Frequently Asked Questions

Why not strike a tuning fork on the table?

Hard surfaces excite unwanted overtones, give a clanging start to the note and, over time, dent or bend the prongs, which changes the fork’s frequency.

How should the fork be held and struck?

Hold the fork by its stem and tap one prong against the rubber. Avoid touching the prongs afterwards, as fingers damp the vibration.

Can one activator be used for all fork frequencies?

Yes, one rubber activator serves a full set of forks. Small high-frequency forks may need a slightly firmer tap to give a note loud enough to use.

Is an activator needed for the resonance tube experiment?

It is strongly advised. A clean fundamental note makes the first resonance position easier to hear and keeps the fork’s frequency reliable for calculating the speed of sound.

Is it used for medical hearing tests?

Tuning forks for the Rinne and Weber tests are usually struck on a soft object such as a rubber pad, so an activator is useful in medical and audiology training rooms.

How should the activator be cleaned?

Clean the rubber with a cloth moistened in mild detergent solution and let it air dry. Keep solvents and oils off it, since they soften or crack rubber.

Last Updated: September 2026