Andrés, I found a sample of Shakira singing "Estoy Aqui" on the site www.shakira.net. I was expecting something as bad as Yoko Ono screaming, but I can hear what you mean by the break sound. It is very much like the American Country & Western style that has a break, which I think sounds like a crying sound, as in when a voice is sobbing and weeping and makes a "break" sound. It is common, as I say in Country & Western songs, but Shakira seems to use it constantly while she is singing, several times in just the few seconds of the sound clip I listened to. If this annoys you, believe me, I think it is why some people LOVE and some people HATE Country & Western singers!
We have certainly gone off topic of boy and women sopranos, but it has been a fun thread.