Is anyone out there still listening?

The digital age is killing AM radio, an American institution that brought the nation fireside chats, Casey Kasem’s Top 40 and scratchy broadcasts of the World Series. Long surpassed by FM and more recently cast aside by satellite radio and Pandora, AM is now under siege from a new threat: rising interference from smartphones and consumer electronics that reduce many AM stations to little more than static. Its audience has sunk to historic lows. But at least one man in Washington is tuning in.

Ajit Pai, the lone Republican on the Federal Communications Commission, is on a personal if quixotic quest to save AM. After a little more than a year in the job, he is urging the FCC to undertake an overhaul of AM radio, which he calls “the audible core of our national culture.” He sees AM — largely local news, sports, conservative talk and religious broadcasters — as vital in emergencies and in rural areas.

“AM radio is localism, it is community,” said Pai, 40. AM’s longer wavelength means it can be heard at far greater distances and so in crises, he said.

“When the power goes out, when you can’t get a good cell signal, when the Internet goes down, people turn to battery-powered AM radios to get the information they need,” Pai said.

He admits to feelings of nostalgia, growing up in small-town Parsons, Kan. On boyhood family road trips across the wide Kansas plains, he said, AM radio “was a constant companion.”

But that was then. In 1978, when Pai was 5, half of all radio listening was on the AM dial. By 2011 AM listenership had fallen to 15 percent, or an average of 3.1 million people, according to a survey by Veronis Suhler Stevenson, a private investment firm. While the number of FM listeners has declined, too, they still averaged 18 million in 2011.

Although five of the top 10 radio stations in the country, as measured by advertising dollars, are AM — among them WCBS in New York and KFI in Los Angeles — the wealth drops rapidly after that. In 1970 AM accounted for 63 percent of broadcast radio stations, but now it accounts for 21 percent, or 4,900 outlets, according to Arbitron. FM accounts for 44 percent, or 10,200 stations. About 35 percent of stations stream content online.

“With the audience goes the advertising revenues,” said Milford Smith, vice president for radio engineering at Greater Media, which owns 21 stations, three on AM. “That makes for a double whammy.”

Nearly all English-language AM stations have given up playing music and even a third of the 30 Major League Baseball teams now broadcast on FM. AM, however, remains the realm of conservative talk radio, including roughly 80 percent of the 600 radio stations that carry Rush Limbaugh. Talk radio has helped keep AM alive.

But why try to salvage AM? Critics say its decline is simply natural selection at work, and many now support converting the frequency for use by other wireless technologies. A big sign of AM’s weakness is that one hope for many of its stations may be channeling their broadcasts onto FM.

Not so fast, said Pai, who has been pushing the FCC’s interim chairwoman, Mignon Clyburn, to put the revitalization of AM high on the agency’s agenda.

“I’m obviously bullish on next-generation technology,” Pai said. “But I certainly think there continues to be a place for broadcasting and for AM radio.”

Pai wants to eliminate outdated regulations, for example, like one that requires AM stations to prove that any new equipment decreases interference with other stations, a requirement that is expensive, cumbersome and difficult to meet.

Pai also wants to examine a relatively new technology known as HD Radio, which has allowed some stations to transmit a digital signal along with their usual analog wave, damping static. (HD Radio is a brand name; it does not stand for high definition, as in HDTV.) But some critics still fault the FCC for allowing too many broadcasters to crowd a relatively narrow AM band of airwaves.

In the longer term, Pai said, the FCC could mandate that all AM stations convert to digital transmission to reduce interference. Such a conversion, however, would cost consumers, who would have to replace the hundreds of millions of AM radios that do not capture digital transmissions.

Finally, Pai wants the FCC to consider what are called FM translators, which send duplicate AM broadcasts over FM airwaves and help to reduce interference. In 2009, the FCC granted permission to AM stations to use such translators.

“Our business has improved rather dramatically” since the conversion to dual bands, said Bud Walters, owner of Cromwell Group, which operates 23 stations in four states, six of them on the AM band and five of which share translators.

The FCC has said it is behind Pai, although it is a long way from committing to the overhaul he envisions. In August it approved requiring the builders of any new radio tower to compensate an AM station if the tower interferes with the station’s broadcast.

Pai said that unless the problems with AM are fixed, people will keep fleeing. “There are plenty of other options,” he said. “They will switch the dial to something else.”