Candidate: "I hope you don't mind me putting on some noise cancelling headphones while I work on this problem, please tap my shoulder if you have any questions.

Candidate: "I hope you don't mind me putting on some noise cancelling headphones while I work on this problem, please tap my shoulder if you have any questions." interviewer (thinking: "Ah! Finally we have a proactive self-reliant candidate who knows his own strengths and weaknesses!"): "Don't bother, you're hired. Let's go to HR so we can work out the details."