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I read that wine bottle produces sound when u blow sideways onto its rim because some frequencies of the white noise produced in your mouth gets amplified when they match the natural frequency of the bottle. But is the tight neck of the bottle necessary for this to happen? If I blow into a closed end tube with uniform width, can't I produce the same effect? Why do I need the small opening?

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  • $\begingroup$ Using a cavity means it can be shorter than a tube... $\endgroup$ – Solar Mike Feb 24 '20 at 5:08
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This phenomenon is known as flow-induced resonance. We learned about this in the submarine Navy, as water flowing over an open hole in the deck will produce a tone, and making tones is a bad thing for subs. The only links I could find for this were to scientific papers about the effect.

You personally need the small opening because you can't produce enough flow across the bottle if the opening is large. But a large enough flow would work on any size hole/tube/bottle combination, although the resulting resonance may be outside a human's perceivable frequency range (20 Hz to 20 kHz for young healthy individuals).

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    $\begingroup$ Nice description, Scott. This link describes the physics behind the flow-induced resonance (also called Helmholtz Resonance). newt.phys.unsw.edu.au/jw/Helmholtz.html The concept is the air in the neck of the bottle acts as a spring-damper system. The frequency is derived using the equation of motion for the air and simple harmonic motion. The derived equation for frequency is a function of the speed of sound, plenum volume, neck cross-sectional area, and effective length. As Scott pointed out, the larger the cross-sectional area of the hole, the higher the frequency of the resonator $\endgroup$ – mechcad Feb 28 '20 at 14:39

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