Audimeter - Patented electronic
device, (a.k.a. "the little black box") used by the A.C. Nielsen
Company (now called Nielsen Media Research) to monitor what television programs a viewing household is
watching at any given moment.
Originally designed to attached to radios, the Audimeter
was placed into households nationwide to record
the listening/viewing patterns. No household is a member for more than five
years with 20% of the participants removed from the program each
"The Audimeter is designed to
record with a stylus on moving tape every twist of the radio
switch and dials. It registers programs received, whether a
program was tuned de liberately or found by dial twisting,
whether it was heard through the full period, tuned out at any
point, or kept on only after unsuccessful search for something
better. Eliminating memory and other human fallibilities from
listener-interest testing, Audimeters should tell advertisers
just what audience he has and precisely what in his program,
if anything, drives an audience away. Independent of
telephones, the survey should sample the 13,000,000 radio
owners who are without phone service.
-- Time, May 16, 1938
The Audimeter was originally invented by Louis Woodruff in
1930 to record what radio station any particular household was tuned
into. The first television monitoring was done in September, 1950.
As of September 1, 1987, the traditional Audimeter was
replaced by a more complex unit called a "People Meter" which
determined additional viewing factors such as sex and age.