A cavity-type RESONATOR so constructed that it will vibrate only at a particular FREQUENCY, giving off little energy to the outer medium, and therefore resonating for a considerable length of time. It was developed by the German physicist Hermann von Helmholtz in the 19th century to analyze the HARMONIC components of a COMPLEX TONE, but has since been superseded by more sensitive electronic devices.
However, large-scale Helmholtz resonators have been used recently by acousticians in perfecting the design of the celebrated Sydney Opera House. The basic design of the resonator as an enclosed air space with a single aperture is similar to the body of the violin or guitar.
Compare: AMPLIFIER, EIGENTON, FOURIER ANALYSIS, RESONANCE, SOUND ANALYSER, SOUNDBOARD, SYMPATHETIC VIBRATION.