South Korean teenagers are so attached to their mobile phones that some researchers are classifying them as 'addicts', according to recent reports.

Almost a third are obsessed with their phones to the point that they sometimes imagine hearing them ringing when they are not.

Forty per cent send over 1,000 text messages every month, and a similar percentage of students say they habitually send or receive text messages or play games during classes.

These and other findings are contained in a survey of 1,100 mobile phone users, aged 14 to 19, which was carried out last month by Korea's Far East University on behalf of the country's Ministry of Communication. 

According to the survey, a fifth refused to be parted from their phones even while bathing.

Mobile games, played by 40 per cent of Koreans, are also causing concern. One 22 year-old university student told a local newspaper that he played games on his phone three to four hours a day and that during classes he and many of his classmates sat at the back of the class surreptitiously playing.

Another said that he kept one phone for calls, and one for games. A 27-year-old office worker interviewed said that he sneaked into the office toilets to play mobile games four or five times a day.

A third of the survey respondents reported auditory hallucinations, for example 'hearing' their phone ringing when it is not. "Even though I set my cellphone to vibrate when calls come in, I sometimes hear my phone ringing," a female high-school student told the JoongAng Daily. 

Young people in South Korea are among the most wired in the world. Almost 80 per cent of the country's 48 million people have mobile phones, according to Jong In Yang, an analyst with Korea Investment and Securities. 

Among teenagers, owning a mobile phone is seen as essential to having a normal social life; mobile device ownership is heavily concentrated in the hands of the under-40s, earlier research has shown.