Loud hair - with white beads that make a click-clack noise with every movement - is one thing. But for a teenage debutant to really make herself heard above the din of the US Open, she needs more than that.
Try "warrior spirit", ambition, and the first indications that her serve was something quite special. Lifting a trophy helps, too: nothing speaks louder in New York City than winning. Twenty years ago, in the late summer of 1998, a 16-year-old Serena Williams didn't exactly ease herself quietly into the US Open, as most teenagers tend to. That wasn't her style. Or even possible, with her mixed doubles partner that summer, Max Mirnyi of Belarus, telling wtatennis.com how the American's hair was "very loud".
"I will never forget Serena's hairstyle - she had very loud beads that made a noise with every step," Mirnyi recalled in an interview, though the noise can't have been that off-putting for him as they won the title, the first of many triumphs for Williams at Flushing Meadows.
From the beginning, Mirnyi could sense that Williams was a talent. What he did not foresee was that she would become such a force in the game - the following year, Williams would score her first Grand Slam singles title at the US Open, and this summer victory would see her equal Margaret Court's all-time record of 24 singles majors.
"I felt like something was cooking up, but I had no idea Serena would go on to be this successful," Mirnyi said.
Asked that summer what they had in common, Williams replied: "We both like reggae." During changeovers, Mirnyi and Williams would chat about music, movies or food, perhaps sometimes even strategy. But when play resumed, Williams would go back to being "fierce". For someone so young, Williams showed remarkable qualities during that run to the 1998 mixed title, which was the second of their Grand Slam victories that summer, after Wimbledon.
"I saw some of Serena's fighting spirit back then," said Mirnyi, who is himself known as 'The Beast from Belarus'.
"We had some tough matches on the way to the title, and despite the fact she was so young at the time, she had the fierce fighting spirit of a mature warrior."
Williams also already had a powerful serve, which she has since developed and improved, turning it into arguably the greatest shot in the history of the women's game. "Over the last 20 years, Serena has definitely matured as a player, but the physical part was already there back then," recalled Mirnyi. "I think her free motion, her physical strength and general flexibility have helped her to have a dominant serve during her career. There is no doubt that she has one of the best serves of any female player in history."
In Mirnyi's analysis, the teenager he partnered to glory at the 1998 US Open has gone on to become the GOAT, or greatest of all time: "It's hard to argue with her records - individually, in doubles, as part of a Fed Cup team, at the Olympics. She is the best."