The number of over-the-air-only TV viewers in the U.S. increased from 42 million last year to about 46 million, and makes up 15% of all TV households, per research from Knowledge Networks. The report also found that 4% of TV homes, or 5 million households, have canceled their pay service, with 70% doing so to cut costs and 30% because they didn't think the pay programming was worth the expense.

According to a new Knowledge Networks survey, the number of Americans now relying exclusively on over-the-air TV is 46 million, up from 42 million a year ago.

Knowledge's just-released 2011 Ownership Survey and Trend Report found that 15% of homes rely solely on over-the-air signals.

"As we've seen for the past few years, over-the-air households continue to make up a sizeable portion of the television viewing landscape," says David Tice, vice president and group account director of KN's Media practice. "Our research reveals that over-the-air broadcasting remains an important distribution platform of TV programming, and that the estimated number of broadcast TV households in the U.S. has grown."

Those over-the-air homes tend to skew toward lower income and minority viewers, according to the study, with 23% of homes making under $30,000 per year relying only on over-the air signals. The survey found that 23% of Hispanic homes are broadcast-only.

That National Association of Broadcasters has been arguing that the continuing, and growing audience for their service is one of the reasons that the FCC should not be too quick to move broadcasters off their spectrum in favor of wireless broadband.