Sympathetic resonance

Source: Wikipedia, the free encyclopedia.
(Redirected from
Sympathetic vibration
)

Sympathetic resonance or sympathetic vibration is a

coupled oscillators
, in this case coupled through vibrating air. In musical instruments, sympathetic resonance can produce both desirable and undesirable effects.

According to The New Grove Dictionary of Music and Musicians:[2]

The property of sympathetic vibration is encountered in its direct form in room acoustics in the rattling of window panes, light shades and movable panels in the presence of very loud sounds, such as may occasionally be produced by a full organ. As these things rattle (or even if they do not audibly rattle) sound energy is being converted into mechanical energy, and so the sound is absorbed. Wood paneling and anything else that is lightweight and relatively unrestrained have the same effect. Absorptivity is at its highest at the resonance frequency, usually near or below 100 Hz.

Sympathetic resonance in music instruments

Sympathetic resonance has been applied to musical instruments from many cultures and time periods, and to

floating bridge
.

Certain instruments are built with

string trees near their tuning pegs. Similarly, the string length behind the bridge
must be made as short as possible to dampen resonance.

Historical mentions

The phenomenon is described by the jewish scholar R. Isaac Arama (died 1494) in his book "Akeydat Yitzchak"[3] as a metaphor to the bi-lateral influence between the human being and the world. Every thing a person does resonates with the entire world and thus causes similar acts everywhere. The human is the active string, the one that is being struck, and the world is the passive instrument that resonate to the same frequencies that the human activate in himself.

References

  1. ^ von Helmholtz, Hermann (1885). On the sensations of tone as a physiological basis for the theory of music. Longman. p. 36.
  2. ^ Lewcock, Ronald; et al. (2006). Sadie, Stanley; Tyrrell, John (eds.). "Acoustics". Grove Music Online. Oxford University Press. "Resonance, reverberation and absorption" section. Retrieved 17 August 2016 – via OxfordMusicOnline.com. This is the online edition of The New Grove Dictionary of Music and Musicians, Second Edition, with newer revisions.
  3. . Gate 12:2, "The melody of the world". Unfortunately the English translator wasn't familiar with sympathetic resonance and changed the text completely, so the idea described can only be read in the original Hebrew text.