"In-Stat: Digital Radio Set to Take Off"

"In 2006, 73 percent of respondents to an In-Stat U.S. consumer survey
were aware of HD Radio on some level."

The survey was conducted in English only

"Sirius, XM, and HD: Consumer interest reality check" (Alexaholic)

"While interest in satellite radio is diminishing, interest in HD
shows no signs of a pulse."

The survey was conducted in English only

This just confirms, the lack of interest for HD Radio, on Google
Trends:

The survey was conducted in English only