<What to prepare

Triangle
The key is to check the shape, size, thickness, and material. Different materials will change the nature of the sound emitted. Also, the nature of some sounds will change depending on the different peeters that are struck.

Fixtures
The triangle does not sound when held in the hand and tapped as it is. The following fixing devices are required. Stand, string, cord, clip, etc. The nature of the sound emitted from the triangle will vary slightly with different fixing devices.

FFT analyzer and other equipment capable of recording the results of frequency analysis
In our experiment, we used an iPad Air to analyze the sound of the triangle using the free frequency analysis app iAnalyzer lite. (We later upgraded to iAnalyzer, which costs $3,600 and can record a large number of data.)
*The application can also be used on iphone, so anyone can use it easily and for free!

＜1>

Fix a triangle of your choice.

＜2>

You can set the conditions and sound the triangle as you like.

＜3>

Record the sound made using an ipad microphone fixed at a certain distance and direction from the triangle and the app.

＜4>

The obtained frequency analysis results are analyzed and compared with other results for verification.