More than a quarter of British companies have banned MP3 players because more than one in five workers are tuning out of the workplace, according to a survey by Woods Bagot.

It found that some 22% of employees use their MP3 music player for up to three hours a day in offices, where listening to music has become another way of shutting out colleagues in open plan desk areas.

Banking and legal firms were the least tolerant of iPods, while companies in the traditionally relaxed marketing and media sector were the most iPod friendly.

The research also claimed a wedge was being driven between older members of staff and younger workers from the so-called “iPod” generation.