Why does a whistle sound louder when you blow harder?

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Discussion Overview

The discussion centers around the phenomenon of sound intensity in whistles, particularly why a whistle sounds louder when blown harder. Participants explore concepts related to air pressure, vibrational amplitude, and the characteristics of sound production in musical instruments and whistles, touching on aspects of acoustics and resonance.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants suggest that blowing harder increases the dynamic pressure in the whistle, translating into louder sound and potentially higher pitch.
  • Others draw analogies to musical instruments, noting that increased force leads to greater amplitude while frequency remains constant.
  • One participant mentions the role of resonance in the air stream within the whistle, proposing that increased blowing pressure may slightly alter frequency due to changes in air density.
  • Another participant argues against the idea that frequency changes with increased pressure, using the example of a klystron to illustrate that power can increase without altering frequency.
  • Some participants discuss the effects of lip tension and the characteristics of the resonant cavity, debating whether these factors influence sound production.
  • There are references to experiments involving gas mixtures and vortex tubes, suggesting potential thermal effects on sound but without definitive conclusions.
  • One participant raises the idea of side bands in sound waves, noting that while they can be amplified, they do not equate to the power of the primary sound.

Areas of Agreement / Disagreement

Participants express a range of views on how sound intensity and frequency are affected by blowing harder into a whistle. There is no consensus on the exact mechanisms at play, with multiple competing explanations and analogies presented throughout the discussion.

Contextual Notes

Some participants acknowledge limitations in their understanding of acoustics and the complexities of sound wave behavior, indicating that further exploration and clarification may be needed.

  • #31
My point is oftentimes an elegant viewpoint can be realized by comparing something to a simpler system.

Comparing a magnetron to a whistle to understand some of the generalties and perhaps some finer details of the magnetron is valid.

Doing the reverse to understand a whistle, is not.

As for the keyhole. Do you believe that the wind is coming across the opening? or into the opening?
 
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  • #32
A typical pea whistle goes through several steps when it is used.

1.) Air enters the mouth piece
2.) Air hits the bevel
3.) Air pressure becomes so great in the air chamber, it becomes released through the whole, allowing the process to start all over again.

However, the pea of the whistle interrupts the flow of the air and changes the rate of air packing and unpacking inside the air chamber, therefore producing your sound. The air inside a whistle chamber packs and unpacks 263 times every second to make the note middle-C. The faster the packing and unpacking is, the higher-pitched the sound the whistle creates.

As proven in this experiment, (http://www.speech.kth.se/prod/publications/files/qpsr/1987/1987_28_1_039-055.pdf) pitch and the volume of a sound often times have a direct correlation. And, to anyone that has played an instrument, you would know that higher-pitched sounds are harder to play at soft volumes, and cannot be heard at the same volume as lower notes.

Please, correct me if I'm wrong. I'm here to learn, not shove answers down people's throats. :)
 

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