"dave" wrote in message
m...
David Eduardo wrote:

"Telamon" wrote in message
...

But about 95% of measured listening occurs inside the 64 dbu contour,
and
80% is inside the 70 dbu contour.

As defined by the ability of HD to perform at all. A self fulfilling
outcome.


I should have been clearer... 95% of analog FM listening is inside the 64
dbu contour.

How do you know this? How do you define listening? PPMs that pick up the
radio behind the counter when you buy a pack of smokes? The radio in the
taxi?

We know it after several different parties analyzed literally millions of
Arbitron diaries over a multi-year period. Diaries include the home and work
ZIP code, and since 70% of listening occurs in those two locations, it's a
perfect base. Diary ZIP code returns by station were laid over maps of
coverage and the results tabulated... and we got the figures cited.

This analysis, also done separately by Arbitron internally, resulted in both
the AM and FM signal based crediting system for stations or shows available
on more than one station in a general area; Arbitron's ascription process
first uses best signal to make a decision, and if neither station available
has a good signal, a random number generator determines who gets credit. But
the base here is the same study... where is each station listenable under
normal circumstances.