Yuor best bet woild be to go through the publisher, they usualy hold the copyrights. There may be a small fee, probably will be which usualy isn't too much.

I've looked into the laws and on some points they are very clear, basicl, use someone elses original material, it doesn't matter what the length of it is, and you'ld better get or pay for permission. Too other points where the laws are a little vague.

From a personal perspective, Phillip K Dick was my father in law, my ex was his step daughter. Her sister who was PKD's daughter has been cheated out of a subsantial amount of royalty money from people who have sampled Blade Runner audio over the years. The rights to use clips doesn't cost that much, you have a clear mind and don't have to worry about being taken to court and the recpients of the royalty money recieve what is rightfully thiers.