FILM is a powerful medium. The question is, how is that power used?Paul Cox brought his "A Woman's Tale" to the Telluride Film Festival over Labor Day weekend. The crusty filmmaker raised an angry voice against exploitative American film, at the same time pleading for a more balanced and heartening cinema. His own film is a delicate testament to an elderly woman's creative response to the harshest vicissitudes of life. Tousled and earnest, Mr. Cox spoke sadly of the misuse of the power of film: "I cannot understand how they can spend $100 million on 'Terminator' and I don't know how much on 'Silence of the Lambs this is what cinema has become. "I find 'Silence of the Lambs,' for instance, one of the most insidious, awful films I've ever seen," Cox says. "It's disguised exploitation.... What have we come to? Is mankind in such despair that it is conditioned to celebrate a serial killer? The whole of Ethiopia could have been fed for a year on what it cost to make these films. "I find it very frustrating," he continued, "because America has such wonderful talent. Walking around Manhattan you find the world. It's very exciting, but I never find that excitement in American movies - that real sense of throbbing life of the country, the amazing artistry of a place like Juilliard School of Music.... There are very fine American artists who will never get a voice in film." Cox points out that the United States film industry controls most of the major markets and outlets world wide, and that one can see American movies in every major city of the world. He says that one of the most extraordinary inventions of the 20th century is being almost totally abused. "If these films brought peace and hope and happiness to people, it would be marvelous, but they don't. These fantasies are very dangerous.... The voice of the cinema comes from America and if it were a more tuned-in voice it would enrich the world." Cox contends that art cannot be made by committee. He says that films based on exploitation or which concede to mediocrity areof no benefit to mankind. An artist speaks with his or her own voice, Cox says, and those who have left some mark are those who spoke with their own voice rather than by formula. So many filmmakers condescend to the public, he says, yet the public is perfectly capable of understanding more than it's given credit for. "I have great faith in the individual," he says. "There is always so much goodness hidden within the human race and within the individual that you must never put them down or patronize them."