You may be thinking of a specialized kind of singing in which a singer shapes his/her vocal tract to amplify overtones or harmonics (Merriam-Webster) of the fundamental frequency (Georgia State University Physics & Astronomy). This type of singing is often called "throat singing" or "overtone singing." The resulting sound is a lower pitched "drone" that does not change much, along with higher-pitched sounds that are manipulated to make tunes.
Encyclopedia Brittanica Online has a general overview of Throat Singing. There are various styles of overtone singing. Alex Glenfield's YouTube video demonstrates seven of them but does not describe them in terms of how they are produced. Anna-Maria Hefele has a video that includes some spectrograms and explanations. There are many other videos on YouTube of various people--men and women--doing harmonic/overtone/throat singing.
As for your phrase-request, I would say the phrase in English would be "throat singer."
I could be way off base here--you may be looking for something as simple as a man who can use a falsetto voice--but it seems from your phrase "two voices" that you are looking for throat-singing.