WASHINGTON — It wasn't too long ago that a kid with a stereo and television in his room might have been the coolest on the block. Now, that just makes him one of the crowd.

In the past five years, many children's rooms have evolved into multimedia centers, with cable or satellite hookups, computers and video-game consoles.

For instance, 20 percent of youngsters age 8 to 18 can surf the Web from their bedrooms, double the figure from 1999, according to a Kaiser Family Foundation survey released yesterday.

That has helped turn kids into "media multitaskers," researchers suggest. Nearly one-third of kids say they chat on the phone, surf the Web, instant message, watch TV or listen to music "most of the time" while doing their homework.

What effect this behavior has on the often fragile ability of kids to focus is unclear because detailed research is fairly new, said Vicky Rideout, the foundation vice president who directed the study.

"We are not necessarily saying that kids spending more time with more media is a bad thing," she said. "This is something all parents have to decide based on what age their kids are, how they are doing in school and the parents' own values."

Kaiser surveyed more than 2,000 third-graders through 12th-graders between October 2003 and March 2004 about their nonschool use of TV and videos, music, video games, computers, movies and print. The study included nearly 700 people who kept seven-day "media diaries."

On average, kids devoted six hours and 21 minutes a day to recreational media use, an increase of just two minutes from 1999, the Kaiser study found. That still amounts to more than 44 hours a week — four more hours than a parent's typical work week.

But 26 percent of kids said they "multitasked" when using any form of media, compared with 16 percent five years earlier. That could mean a child is downloading music over the Internet while playing video games, or chatting online while watching a favorite TV show.

The proportion of kids who had a VCR or DVD player in their room rose from 36 percent to 54 percent.

A majority of kids — 53 percent — in the Kaiser survey said their families had no rules for TV viewing.