Sympathetic Vibration

An oscillation produced in an object which resonates at the same frequency, or a harmonic multiple thereof, as that present in a sound wave in contact with the object.

See: Eigenton, Helmholtz Resonator, Resonance, Resonator. Compare: Acoustic Radiation.

For instance, various body cavities and organs may be set in vibration by infrasonic vibration and low frequency sounds. Since most materials used for construction have low resonance frequencies, sounds in this range will be transmitted easily through such structures, such as is commonly experienced with bass notes of music travelling through walls and ceilings.

A common illustration of sympathetic vibration is to sound a tuning fork and bring it close to, but not touching, another fork of the same frequency, which will then begin to vibrate sympathetically. If the forks are mounted on resonating boxes, the effect will be stronger and thus heard better. The same effect can be observed by shouting or singing near a set of undamped piano strings.

 Singing into undamped piano strings

 Whistling into undamped piano strings

 Clapping near undamped piano strings