Talking loudly has always been a major faux pas at the office; now, etiquette guides are looking to educate workers on the benefits of speaking softly -- and the dangers of the raised voice. Though many agree that talking loudly, while annoying, will not cost an employee his or her job, there is always the danger that if minor concerns add up, it could affect a worker's rating during performance reviews. Talking loudly may impede advancement within a company, and could alienate a employee from his or her co-workers.
See "The Workplace: When noise grates nerves in the office", Matt Villano, International Herald Tribune, July 12, 2005