Randall Stutman, who for decades has been the behind-the-scenes advisor for many of the biggest CEOs and leaders on Wall Street, once studied how several hundred senior executives of major corporations recharged in their downtime. The answers were things like sailing, long-distance cycling, listening quietly to classical music, scuba diving, riding motorcycles, and fly-fishing. All these activities, he noticed, had one thing in common: an absence of voices.