This file is from Wikimedia Commons and may be used by other projects.
The description on its file description page there is shown below.
Summary
DescriptionAdditive 220Hz Square Wave.wav
English: After every second, a harmonic is added on top a 220Hz sine wave, creating a 220Hz square wave. This file is generated using wavepot.com. The source code can be found here.
Tiếng Việt: Sau mỗi giây, một sóng điều hòa được cộng vào sóng sin 220 Hz ban đầu, tạo thành sóng vuông 220Hz. File được tạo từ wavepot.com. Mã nguồn ở đây.
The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighbouring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
http://creativecommons.org/publicdomain/zero/1.0/deed.enCC0Creative Commons Zero, Public Domain Dedicationfalsefalse
Captions
Add a one-line explanation of what this file represents