[2] Her father, Trịnh Định Kính, was a successful businessman who owned the largest glass factory in French Indochina.

In 1955, when she was 24 years old, she joined the Voice of Vietnam radio station and was chosen to read the English language newscast aimed at listeners in Asia's English-speaking countries.

[3] At this time, she adopted the alias Thu Hương, meaning "autumn fragrance", as it was easier and shorter for her non-Vietnamese listeners.

She made three broadcasts a day, reading a list of newly killed or imprisoned Americans, and playing popular US anti-war songs in an effort to incite feelings of nostalgia and homesickness, attempting to persuade US GIs that the US involvement in the Vietnam War was unjust and immoral.

[1] US Navy ships and personnel were also targeted in her broadcasts, with Ngọ reading out the names of crew members and saying that they were all going to die.

[5][9] There were exaggerated legends of her omniscience, with rumors that she would give clues about everything from specific future PAVN attacks to soldiers' girlfriends cheating on them at home.