Renaud and Sophie Rousseau weren't a terribly likely couple - Renaud was, after all, a successful businessman in a major French company, and came from a well-to-do family, while Sophie Moreau was a fairly poor girl from one of the worse areas in the city, but love does conquer all, and the two had been close since childhood even despite their differences. Lucky enough to have such a good job, the couple were able to live quite comfortably even in an expensive city such as Paris, and so the birth of a son came as a happy blessing.
Sacha was born into the family on December 10th of 1983. While Renaud's job was prosperous, it wasn't enough so as to allow for his son to attend prestigious primary schools, but nonetheless, the boy had a happy childhood. Of course, the patriarch's habit of taking his family along on extended business trips only made things all the more exciting for a growing boy, and frequent trips to London along with lessons in school contributed to the boy's becoming fairly fluent in English as well as French, although the entire business also instilled in him quite an obsession with travel as well. He never was terribly comfortable staying in the same place for too long, although over time he came to accept it as a common necessity.
But, not before that habit succeeded in creating some difficulties in his personal life. He was able to go to university, of course - electing to attend school abroad in the U.K. rather in his home country. Focusing his studies on fine arts, with the intention to select a more specific field later on, Sacha lasted barely a year and a half before growing bored with university and lying to his father about an increase in tuition in order to get money to leave Britain and tour Europe for the summer of his 20th year.
It was on this extended vacation that Sacha discovered his peculiar ability, although for quite a while he chalked it up to coincidence. At a particular mountain range, he shouted a few phrases in order to hear the echo, as people tend to do in such places, but in unconsciously raising the pitch of his voice, his shouts resulted in the breaking of a few nearby rocks. … Obviously a coincidence.
However, similar coincidences occurred afterwards that led him to believe that it may have been doing it after all. A startled yelp would be accompanied by the sound of a coffee mug breaking, a whistle to get someone's attention by the shattering of street lights. Eventually, even denial can't explain things away, and while Sacha certainly didn't want to think anything was strange, it got to the point where he was forced to admit that he had a problem.
He does not, however, embrace his gift - and while he doesn't think of it as a curse, he hasn't gone out of his way to develop it, either. When he eventually ended his European tour and decided to settle down in New York City for a while, he opted to refrain from registering as Evolved, both because at the time he had no plans to ever make use of his ability, and because frankly he didn't find it to be any of America's business. Perhaps if and when France requires registration he'll opt into it, but he has no interest in giving America any more information about himself than required.
Of course, by the time he did visit the country it was after the bomb had dropped, and the Frenchman was lucky enough to have no relatives in the city at the time of the disaster - not that he would have worried in any case either. His parents still live in France, naturally, and business trips don't take them outside of Europe. Sacha does have sympathy for the victims of the catastrophe, but tends to view the whole business in the detached method of an outside observer.
Despite having earned back the money through gambling and saving at his job, his father still isn't speaking with him. C'est la vie.