Weber Shandwick's technology division will manage the account along with its sister lifestyle agency Slam PR.
The Sonos multi-room music system comprises a portable controller and a number of 'zone players' - or speakers. The system allows different music to be played in different rooms, using the internet to stream music from services such as Napster and Last.fm.
Sonos had concentrated on gaining coverage in the consumer tech media. Weber Shandwick's brief is to target the lifestyle and retail press.
Weber Shandwick won the work after a four-way pitch.