Openverse
free and openly licensed media
Library of Congress Free to Use and Reuse
various content that is free to use and reuse
Yellowstone National Park Sound Library
audio/sounds recorded in Yellowstone, available for download/use
cobalt
tool for saving and downloading content from websites, no trackers or ads
Freesound
collection of creative commons sounds
ChipTone
sound effect maker
Audacity
audio editor and recorder