Washington ? Congress might mute screaming TV-ad announcers who press viewers to “buy now!”

Under a proposal to be taken up today, the Federal Communications Commission would limit ad volumes to the average decibels of the TV show during which they appear.

Currently, TV ads can’t be louder than the loudest peak in a show, said David Perry, chairman of the broadcast production committee of the American Association of Advertising Agencies in New York. Ads often seem louder to viewers, he added, because a program’s volume peak rarely comes just before an ad.