Mark conducted a study on office workers, which revealed that “each employee spent only 11 minutes on any given project before being interrupted”.
Kelemen et al. showed that a team of programmers is interrupted through a technical Skype support chat up to 150 times a day.
Different studies report that an interruption during productive hours may take 15 to 45 minutes for the employee to get back on track, fully focused on their assignment. Lifehacker bets on 23 minutes and 15 seconds.
Software development is a creative job that depends on processing large volumes of data and building an extensive model of the application before creating a fix or a new feature.
Composing the right structure in your head takes time and hundreds of considerations (preventing regressions, performance bottlenecks, security issues). An interruption may affect that cycle and get you back to square one.
Office interruptions may be voluntary or involuntary. Printer sounds or casual chit-chat around the water cooler can contribute to distractions, along with calls and other nearby activities. Even a quick question from a fellow colleague may be avoided as it may be a low priority (reoccurring dozens of times a day).
Headphones As Signal?
Headphones are a good indicator of unavailability. Developers may use that simply as an isolation signal. Or they can pick a playlist that boosts their productivity at that point in time – often something rhythmic that’s familiar or lacks distracting lyrics.
You may still get the occasional interruption from a fellow colleague. But reasonable co-workers would only bother you if it’s an important question that requires their attention.
That’s why headphones are crucial for developers in most office environments.