This is an amazing fact. Learning a language is also learning cultural and social factors and when you finally master a language, you can blend with native speakers, mimicking them at first and slowly integrating all of their physical and oral expressions.
While my voice in French is quite "normal", neither deep nor high-pitched, my voice in Spanish seems like one of a giggling teenage girl! Ok, I might be exaggerating but I sound much more higher and younger in Spanish. I think my voice tone is also higher in American English. I am not talking about intonations, because, of course intonations change depending of the language you are speaking, I am really speaking about deep or high-pitched voice sound.
I found a person on Linguaphiles asking the question of voice changes while speaking foreign languages, you can read the answers here.
One time in France, while I was having a drink with my sister and her friends, my sister told me to lower my voice, as, according to her, I was speaking very loud. I then realized that, because I just arrived from Spain, I was still speaking as a Spanish person, which is louder than a French person (at least from a French perspective). I had then to readapt myself to the French correct voice volume! Funny how language really molds and formats us!
Being able to correct and adapt oneself culturally to any kind of situations is a real gift, but it is also a learning experience that never ends.