THE SOUND OF SILENCE is not one you’ll hear at Sonos. Music is a constant presence at the speaker brand’s new Boston office, which was designed with collaboration in mind by IA Interior Architects. It flows through the enormous café that houses biweekly team lunches and streams into numerous conference rooms as well as a designated game area and an outdoor patio. And for employees who want to enjoy a playlist privately, the secret listening room—accessible via a rotating door disguised as a bookshelf—offers sonic solitude.