As video technology became more widely available in the early 1970s, many artists were drawn to the medium's immediacy and ease of reproduction, which allowed works to be shown on television or through other modes of distribution that bypassed the walls of museums or commercial galleries. Serra, known primarily for his large lead and steel sculptures, made a number of films and videos in the late 1960s and early 1970s. Holt, a pioneer of land art, also worked with film, video, and photography throughout her career. 　　In Boomerang—which was broadcast live on a TV station in Amarillo, Texas—Holt's words are fed back to her through headphones with a one-second delay. She describes the experience, in which her words are suspended in time and space, as "a world of double reflections and refractions." As her voice echoes back to her, she continues, "words become like things," disconnected from their individual meanings and from their contexts. This interferes with Holt's thought process and establishes a distance between the artist and her sense of self, an effect intensified when pre-recorded sound samples are played or when glitches in the broadcast cause momentary periods of silence.