Most reproduced program content is effectively monophonic

Evidence

A persuasive justification for monophonic evaluations is the reality that in movies and television programs the center channel does most of the work—a monophonic sound source. The center channel is arguably the most important loudspeaker in a multichannel system. In popular music and jazz stereo recordings, images are often hard-panned to the left or right loudspeakers, again monophonic sources, and the phantom center image is the product of double mono, identical sounds emerging from L and R loudspeakers. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1093

Categorization

• XREF: Connects to the argument in this book’s other chapters about why mono testing remains valid — and to the general principle that the two ears receive highly correlated signals in most real content.