Changing Voice
I have several Chinese coworkers. Two of them have been in the US for a long time, another, I think, is fairly new to the country. The first two sound the same in when they speak either English or Chinese. The third, however, is much louder and I guess outspoken when he speaks in Chinese. I of course have to speak to him in English. He is so soft spoken in English I sometimes have to get closer to him to hear what he is saying. I'm guessing it's a confidence thing.
It reminded me of when I was in college learning Japanese. Most girls, myself included, seemed to speak Japanese in a higher pitch than our English voice. I wonder if it was because most of our exposure to the Japanese language was the animes we had looked into. In a way we were all trying to mimic the cute girly characters. Similar with the guys, they often got much deeper and reminded me of the "manly samurai" characters, wanting to mimic the tough characters they had seen in animes or samurai movies.
So I just wonder if everyone sounds different when they first learn a language, and once they get confident in the foreign tongue do their voices begin to sound similar.