The first successful application for a sound mark was registered in 1978 and was filed by NBC. Thirty-five years out, it is still a notoriously long and difficult process. So when I'm asked by another business owner if they can trademark a sound, I always have to give a "yes, but..." answer for the following reasons.
Dr. Quinton Nottingham, statistician and Associate Professor in the Department of Business Information Technology at Virginia Tech, has established that a rise in trademark registration correlates to a rise in the stock market. The Dow, NASDAQ and the S&P all increase with increased corporate activity.