The classic example of this is breaking a wine glass with sound at the precise resonant frequency of the glass.įurther information: Vibrating string String resonance of a bass guitar A note with fundamental frequency of 110 Hz. Like mechanical resonance, acoustic resonance can result in catastrophic failure of the vibrator. (For mammals the membrane has tapering resonances across its length so that high frequencies are concentrated on one end and low frequencies on the other.) For example, resonance of a stiff structural element, called the basilar membrane within the cochlea of the inner ear allows hair cells on the membrane to detect sound. Acoustic resonance is also important for hearing.

In effect, it is filtering out all frequencies other than its resonance.Īcoustic resonance is an important consideration for instrument builders, as most acoustic instruments use resonators, such as the strings and body of a violin, the length of tube in a flute, and the shape of a drum membrane. It will 'pick out' its resonance frequency from a complex excitation, such as an impulse or a wideband noise excitation. It will easily vibrate at those frequencies, and vibrate less strongly at other frequencies. The term 'acoustic resonance' is sometimes used to narrow mechanical resonance to the frequency range of human hearing, but since acoustics is defined in general terms concerning vibrational waves in matter, acoustic resonance can occur at frequencies outside the range of human hearing.Īn acoustically resonant object usually has more than one resonance frequency, especially at harmonics of the strongest resonance. However, if a piece of metal is placed on a prong, the effect dampens, and the excitations become less and less pronounced as resonance isn't achieved as effectively.Īcoustic resonance is a phenomenon in which an acoustic system amplifies sound waves whose frequency matches one of its own natural frequencies of vibration (its resonance frequencies). Although the first tuning fork hasn't been hit, the other fork is visibly excited due to the oscillation caused by the periodic change in the pressure and density of the air by hitting the other fork, creating an acoustic resonance between the forks. One of the forks is being hit with a rubberized mallet. Experiment using two tuning forks oscillating at the same frequency. For a general description of resonance, see Resonance. For a general description of mechanical resonance in physics and engineering, see Mechanical resonance.

This article is about mechanical resonance of sound including musical instruments.

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