Maya's preschool teacher found this among some old Christmas ornaments, and was very excited to show it to me the other day when I was there to work with the kids. The date on the side is 1979, but may have been made at any time over a number of years as I never changed the copyright stamp that we used on these whistles. This one illustrates very nicely the design system I used in designing this and 5 other whistles -- all based on the basic "police" whistle. Mentally remove the upper portion of the music note, and you have a classic metal (or plastic) pea whistle. We used actual cork balls just like the originals. Blowing on the whistle causes the cork pea to rotate around inside the chamber, with the whistle noise stopping each time the pea passes by the opening. Check out the video/audio below.
I won't go into all the details, but the first designs of "pea" whistles that I did all utilized the same basic blank to create two whistles from each blank. We could create a few hundred blanks, and then later cut out whatever style we needed..... music note, Zwiggle (see picture below), bird, etc. (I can't make my memory bring up the other designs right now) Also shown below is a Saguaro Cactus whistle that I made for my Dad who lived in Arizona for a number of years, and loves all things Arizona!
We usually used the yellow nylon cord loop on the whistles as shown in the music note picture at the top, but for a while we tried using a key chain hook, but these did not sell as well as we had hoped. Below, you can see the opening in the whistle that is the key to the whistle. The whistle is a very simple musical instrument, with air blowing over a hollow space creating a tone. The size of the hollow space determines the pitch. If you take the lower portion of the music note above, and mentally place it over the Zwiggle body, you can see that the exact same whistle blank can be used for both pieces.
More about ZwigglesBelow is the Saguaro Cactus I made for Dad!
Also from the same basic whistle blank.