Mobile phones are becoming an increasingly popular way to listen to music, according to a worldwide survey.
The mobile phone sector is constantly evolving
Nearly one in five of those questioned listened to music via a mobile that played MP3s, reported researchers TNS.
Nearly half of those used them as a playing device on their journey to work, while 23% used them in bed.
The survey was conducted among 6,800 16 to 18-year-olds in 16 countries including France, Germany, Russia and the UK.
Music is the mobile phone application with most potential for growth, TNS suggested, with 35% saying they wanted to use the function more in future.
But the report said people were put off downloading music to mobiles because of inferior quality or not enough memory.
Tacis Gavoyannis, global head of technology at TNS, said the practice was most popular in Korea and Japan.
"I think looking into the future we will see an increase of music on the mobile phone and possibly a decrease in stereo usage," Dr Gavoyannis said.
"I see the UK market getting higher numbers of digital music usage on mobile phones because there will be a tendency, especially with the youth market, to have one gadget with all your tools on it."