File:The Warner Bros.-Seven Arts Animation Sound Effects Library
For those who remember the late 1960s incarnation of Warner Bros. Animation run by Bill Hendricks (best known for having many of its shorts distributed by Warner Bros.- Seven Arts), the sound effects were rather unusual; it had a small portion of the classic Looney Tunes sounds, along with a small portion of the Hanna-Barbera sound effects library (since Alex Lovy had come from H-B to direct for the Warner Bros. cartoons of the era.) The sound library was actually quite limited, especially compared to the vast collections Hanna-Barbera and the original incarnation of Warner Bros. Animation had. When Robert McKimson took over as director in late 1968, some more SFX were brought in, but it still wasn't quite enough. You could imagine the limitations they must've had in their sound effect budget!
Funny thing is, in 2002 when Warner Bros. Animation made "What's New, Scooby-Doo?" they used a nearly identical sound library, but with a few more WB and H-B SFX added, repeated over and over, and a bunch of newly-created "house" sound effects that were used to make the show sound more realistic and less cartoons.
All SFX are by their respective creators/copyright holders!