# Why does a whistle sound louder when you blow harder?

seycyrus, who stated it was a "simple whistle". Maybe the original thread starter should state the type of whistle. Is it a Ford or a Chevy, then intelligent posts can be made. That was all I was trying to point out. Don't forget the details or the details will get you.

RonL
Gold Member
These two last post should illustrate the importance of physics.
"A simple question" about "A simple whistle" yet the details are not so simple.
The vortex tube was mentioned to bring to mind air movement, and how it spins and is seperated into two thermal quanities " air in equals air out".
The same holds true with the whistle, but the discharge is much different. Before i say anything else i should go find my whistle and do some more study -:)

You are 100% right RonL. You can slice it and dice it as many ways as you want to but there is only one answer to the question. The answer on the teachers answer card.

The question is getting more complicated. I am now hearing the door keyhole whistling because of strong wind (you all must have experienced). And the stronger the wind, the higher the frequencies !

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seycyrus
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?

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. :)