The invitation arrived not on letterhead, but as a low, clean 20Hz sine wave hidden in the end credits of a forgotten film.
The "In Selected Theatres" text began appearing alongside Dolby logos as early as the mid-1970s and became a staple from the early 1990s through the early 2010s. Its purpose was functional: it informed audiences that while the film was mixed with advanced Dolby technology, only specific theaters equipped with the necessary hardware could deliver the full audio experience. dolby in selected theatres logopedia