LAS VEGAS, Nev. (AP) _ Virtually all commercial radio stations in the country will go silent for 30 seconds on May 26, broadcasters said Monday, as part of a campaign to show the importance of radio in daily life.

The 30 seconds of dead air time - ''The day the radio stopped'' - will mark the beginning of a $100 million campaign with the theme: ''Radio. What would life be without it.''

The booming voice of actor James Earl Jones will tell listeners that ''for the next 30 seconds this station and others would like you to imagine your life without radio. Imagine if all your days sounded like this. ...''

Following the 30 seconds of silence, Jones will say: ''Thirty seconds seems like a long time, doesn't it? Now think how radio fills that silence for you.''

The radio campaign was announced at the National Association of Broadcasters convention. The NAB also inducted veteran sportscaster Red Barber and pioneer Spanish-language broadcaster Nathan Safir into the NAB's Broadcasting Hall of Fame.

The radio awareness campaign is a joint effort by NAB and the Radio Advertising Bureau.

RAB President Warren Potash said: ''The campaign is intended to increase awareness and appreciation for radio with advertisers and opinion makers and to remind us all that radio's influence is large and powerful.''

The bottom line, he added, ''is to increase radio's share of advertising dollars.''

The campaign also will include on-air commercials and newspaper and magazine ads.

NAB President Eddie Fritts said ''this unprecedented collective action by commercial radio stations marks a new marketing era'' based on psychological research that shows ''radio is a vital part of people's daily lives that they take for granted.''

Fritts said 228 million Americans listen to radio an average of three hours and seven minutes a day. Follow-up surveys will determine if the campaign has increased awareness of radio.

Jerry Lyman, president of Radio Ventures L.P., said 10,000 stations are expected to go silent at 7:42 a.m. local time across the country.

''Not everyone has committed'' at this time, said Steve Berger, president of Nationwide Communications. But Lyman said he had heard of only one station owner so far saying he would not participate.

Lyman said broadcasters expect to hear a few complaints from listeners when their radios go silent.

''We want a reaction,'' Lyman added.

Barber and Safir were honored for their contributions to radio over the years.

Barber began announcing baseball on radio in 1934 with the Cincinnati Reds. He later did play-by-play for the Brooklyn Dodgers and New York Yankees and worked in 13 World Series broadcasts.

Safir is vice president and general manager of KCOR in San Antonio, Texas. He began a two-hour Spanish-language program on KSTA in San Antonio in 1940 and produced and announced Spanish-language programs for Armed Services Radio during World War II.

He also is vice president of Tichnor Media, the largest group of Spanish- language radio stations in the country.