I'm requoting this for context. If you are modifying a CC-BY asset (of any type & version), you must keep the original CC license type and also give an attribution notice. However it is up to you if you want to ALSO be attributed. This means in a README or credits or something, you say:
"Foo.wav" is a derivative of "Foobar.wav" by [Original author], used under CC BY. "Foo.wav" is licensed CC BY by [Your name]
Keep the SAME license type AND version as what the original author used.
If you DO NOT want to be attributed, you MUST still list the attribution for the source of the asset, but can leave your own name off it.
If you are creating an ORIGINAL work (that is 100% yours, not a derivative of any copyrighted nor copylefted thing), you can just say "no attribution required".