• by Erik Sass  @eriksass1, January 26, 2010

Over the last five years, the number of kids and young adults who own an iPod or MP3 player has more than quadrupled, according to a new study released Monday by the Kaiser Family Foundation. The proportion of people between the ages of eight and 18 who own one of these devices jumped from 18% in 2004 to 76% in 2009, representing an increase of 322%.

The average number of radio sets in the homes of these Kaiser respondents decreased from 3.3 to 2.5, and the average number of CD players fell from 3.6 to 2.2 over the same period.

In keeping with these shifting patterns of ownership, the amount of time spent listening to various devices has also changed substantially in the same age cohort.

Of the two hours and 19 minutes of daily music listening by the children and young adults surveyed, 41 minutes (about 30%) was spent listening to an iPod or MP3 player, versus 32 minutes each (23%) for radio and music stored or delivered by computers. Cell phones and CDs trailed with 17 minutes each (12%).

Among teens 15-18, the differences were even more pronounced. Out of an average three hours and three minutes of daily music listening, iPods and MP3 players accounted for 59 minutes (32%), versus 42 minutes for computers (23%), 37 minutes for radio (20%) and 23 minutes for cell phones (13%).

These results will likely be of interest to audio content creators and advertisers trying to establish a connection with younger consumers. Other recent studies have suggested that broadcast radio listening is decreasing among teens, which bodes ill for the medium in coming years.

In June 2009, Nielsen found that just 16% of teenagers around the world consider radio their "primary source" of music, lagging far behind MP3 players, identified by 39% of teenagers as a primary source of music, and computers, preferred by 33% of teens.

In June 2008, Coleman Insights found that daily radio listening by teenagers was on the downswing, losing share to the new media options. Specifically, Coleman found that 84% of the 14-17 cohort listen to music daily on an MP3 player, iPod or computer, versus 78% for radio.

A second Coleman study found that the 15-17 cohort favors iPods and MP3 players as primary destinations for listening to music -- with 41% choosing the personal devices, compared to just 22% for FM radio.

Other studies have found some positive news, but the results tend to be mixed at best. For example, in 2008, Arbitron found that 90% of people ages 12-17 still listened to radio at least once a week, increasing to 93% among adults ages 18-23. But Arbitron also found the average amount of time spent listening to the radio dropped 5% from 19 hours and 32 minutes per week in 2007 to 18 hours and 30 minutes in 2008.