Partial copy paste from their reddit post:
The Sonniss GameAudioGDC Bundle is back!
In celebration of GDC 2018 we are giving away 30GB+ of high-quality sound effects for use in your game development projects. Everything is royalty-free and commercially usable. No attribution is required and you can use them on an unlimited number of projects for the rest of your lifetime.
Visit the website: https://sonniss.com/gameaudiogdc18/
View the license: https://sonniss.com/gdc-bundle-license
OFFICIAL TORRENT: https://sonniss.com/GameAudioGDCPart4.torrent
Once you have downloaded the files, please help by sharing, seeding or uploading them to mirrors. Thank you in advance. I am not sure how much our servers can take.
Full post here.
Previous version of the Sonniss GameAudioGDC can be found in this post.