(1 - mixkit)
(Website)
https://mixkit.co/
(2 - freeanimalsounds)
(Website)
https://freeanimalsounds.org/downloads
(3 - pixabay)
(Website)
https://pixabay.com/sound-effects/
(4 - freesound)
(Website)
https://freesound.org/
(5 - freesoundeffects)
(Website)
https://www.freesoundeffects.com/
(6 - soundeffectsplus)
(Website)
https://www.soundeffectsplus.com/