Complex sentence: The original expectation was that CinemaScope would use a separate film for sound (see Audio below) thus enabling the full "silent" 1.33:1 aperture to be available for the picture with a 2:1 anamorphic sqeeze applied that would allow an aspect ratio of 2.66:1.
Split into simpler sentences: The original expectation was that CinemaScope would use a separate film for sound (see Audio below) thus enabling the full "silent" 1.33:1 aperture to be available for the picture. With a 2:1 anamorphic sqeeze applied that would allow an aspect ratio of 2.66:1.